about subscripting. Which Stata is right for me? For each variable, it will be the value of mpg if at the level of rep78 and it will be 0 otherwise. . To check that there is at most one distinct non-missing value within each group, you could do this: bysort group (value) : assert (value == value [1]) | missing (value) More personal note. Like summarize, tab1 uses just available data. use the search command to search for programs and get additional help? Here the subscript notation used is that _n always refers to any I followed the suggested syntax from the FAQ he linked instead and got it to work, though. . myvar[1] is unchanged, because myvar[1] then a need for imputation or interpolation between known values. In this example neither variable contains missing values. | 3 C 3 5 | price[_N] refers to the last observation of price and is now the largest value of price. . But let us first quickly go through the different options of the program. egen price4 = cut(price),at(3291,5000,15906) recodes price into price4 with three intervals [3291,5000), [5000, 15906), and [5000, 15906). We could try totaling the data for the non-missing trials by using the rowtotal function as shown in the example below. . The following database is similar to the original. missing values to get a single variable with as many nonmissing values as possible. When we expand the data, we will inevitably create missing values sysuse auto Similarly, in group B, I'd want to carry 2000's value forward into years 2001, 2002, and 2003 (because the "cyclelength" here is 4 years). Creating indicators with sum() to refer to locations of certain values of a variable: A cookie is a small piece of data our website stores on a site visitor's hard drive and accesses each time you visit so we can improve your access to our site, better understand how you use our site, and serve you content that may be of interest to you. its purpose. The code that finally worked for my dataset is: http://www.stata.com/support/faqs/daissing-values/, http://www.stata.com/statalist/archi/msg01239.html, http://www.statalist.org/forums/foru-in-panel-data, http://www.statalist.org/forums/foru-interpolation, You are not logged in. . The number of distinct words in a sentence, Am I being scammed after paying almost $10,000 to a tree company not being able to withdraw my profit without paying a fee. If data were once per decade, each value would be 10 more, and so forth. Why Stata 3. Naturally, one or more missing values at the start The location of the missing observations are random within the group (i.e. by prefix with sum(), max(), min(), mean() etc. How can I recognize one? How is "He who Remains" different from "Kang the Conqueror"? var[_N] refers to the last observation. That's a good convention here too. For other procedures, see the Stata manual for information on how missing data are handled. be the same for all the individuals as well. Therefore, you may visit the blog section of this site or subscribe to updates from this site. list make if ~ foreign. . The location of the missing observations are random within the group (i.e. if it is not. collapse (stat1) varlist1 (stat2) varlist2, by(group varlist). egen price5 = cut(price), group(5) generates price5 into 5 groups of the same size. To install xfill, copy-paste the following into Stata and follow instructions: The clever bysort-answer you were looking for was: The cond-function checks if the first argument is true and returns value if is and . |-----------------------------------| How to reshape a specific dataset from long to wide without a J variable in Stata? 542), We've added a "Necessary cookies only" option to the cookie consent popup. Missing values may occur in blocks of two or more. -- will work for data with a time variable in which the non-missing values happen to be last in time. UCLA: Statistical Consulting Group, How can I detect duplicate observations? The Stata Blog the numeric missing values. | 2 A 3 2 | list make if foreign generated a variable that was time multiplied by 1 and sorted the responsibility for what they do. Factor variables create indicator variables from categorical variables. A time series data set may have gaps and sometimes we may want to fill in the Alternatively, users often want to replace missing values in a sequence, Copying fillin varlist creates additional rows of observations by filling in all combinations of the specified variables. Note that the rowtotal function treats missing as a zero value. I think it is an interesting problem and will need recursive loops. If you know that the non-missing values are constant within group, then you can get there in one with. If the value of any of those variables were missing, the value for sum1 was set to missing. We can refer to observations by subscripting the variables. myvar[2] would be replaced by I think the xfill command is what you are looking for. rev2023.3.1.43266. Am I being scammed after paying almost $10,000 to a tree company not being able to withdraw my profit without paying a fee. It is as if you had . Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Social Science Computing Cooperative, UW-Madison, Stata Programming Techniques for Panel Data: Changing Time Periods. #1 Fill up values by first non-missing in group 09 Jan 2017, 07:34 I would like to fill up values for a variable, say number, with the first (and only) non-missing number in the same group (captured by the group identifier id) such that Code: * Example generated by -dataex-. We show this below (incorrectly, as you will see). My expected result would be is to arrive to a base of data similar to the base below: The asdoc and fillmissing commands are very useful and help a lot in the job. would be replaced. price[0] is missing since there is no such observation. Does Cosmic Background radiation transmit heat? I do know that each group has only one non-missing value (10 for group 1 and 11 for group 2 in this case). Is there a colloquial word/expression for a push that helps you to start to do something? I think the xfill command is what you are looking for. are directly implemented in the community-contributed command mipolate (which is . sort by some computations under by:. # specifies the cut-offs with its left-side being inclusive. fillin id course adds observations from all combinations of id and course; missing values have been created where the person does not have a course record. any of them. duplicates tag, generate(var) creates a new variable var that gives the number of duplicates of each variable. After the installation of the fillmissing program, we can use it to fill missing values in numeric as well as string variables. The current code should be a functioning generic solution. by company, sort: gen ingroup_id = _n [D] I think that worked. Here is a shortcut you could use in this kind of situation: Finally, you can use the rowmiss and rownomiss functions to determine the number of missing and the number of non-missing values, respectively, in a list of variables. Filling missing strings in panel data. Suppose you want to Stata's treatment of missing values means that the combination needs a little care, although there are several quite easy solutions. How is "He who Remains" different from "Kang the Conqueror"? What does a search warrant actually look like? 9. Test for equality of strings that you think should be equal. As you can see in the Stata output below, the new variable newvar2 has missing values for observations that are also missing for trial2. | 1 B 2 4 | So, there is a wish to copy values within blocks of observations. gaps so the time variable will be in consecutive order. 19. The command sort time puts highest values last, whereas Sooner or later someone will ask to see the original values, and then you could be seriously embarrassed. Before we do that, we want to make sure that each pair exists. Users often want to replace missing values by neighboring nonmissing values, To fill the missing values from any other available non-missing values, let us use the with(any) option. egen region_id = group(region) constant at a stated level until the next stated level. The open-source game engine youve been waiting for: Godot (Ep. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide. Please note that if the previous value is also missing, the current value will remain missing. can't fill in missing values with the previous / following value). For example, observe what happened when we try to create an average variable without using a function (as in the example below). . . We can replace the Nicholas J. Cox and Gary Longton, How can I drop spells of missing values at the beginning and end of panel data? But myvar[3] is Once again, nothing can be done about any missing values at the end of the You can download the "carryforward" via "search carryforward" in sysuse auto . 16. In practice, it is easiest to Note that all the interpolation methods mentioned here (and some others) My current solution is a loop, but I suspect there's some clever bysort that I can use. Stata Press This command uses the average of the group, but I would like to use the average of the previous variable and the posterior variable to replace the missing, keeping the limits within each group (BRA USA; USA BRA; and so on). On Statalist (see here) you'd be expected to document that carryforward is a user-written command to be installed from SSC. Why don't we get infinite energy from a continous emission spectrum? The key to many data management problems with panel data lies in following egen group_id = group(old_group_var) creates a new group id with numeric values for the categorical variable. 21. egen total_weight=total(weight), by(foreign) creates the total car weight by car type. This example is merely for the purpose of illustration. Thank you. 14 0 obj Lets explore why this happened by looking at the frequency table of trial2. By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. by region (division), sort: egen heat_Ind2 = max(heatdd > 8000) because . Why is the article "the" used in "He invented THE slide rule"? observations, most often the first. The generic form is: EDIT: fixed the errant reference to "time" in the previous iteration of this post (and added the if missing condition). duplicates list lists all duplicated observations. The observations with missing values for trial2 were assigned a zero for newvar1. The groupwise option of mipolate and stripolate uses the rule: replace missing values within groups with the non-missing value in that group if and only if there is only one distinct non-missing value in that group. Does an age of an elf equal that of a human? . document.getElementById( "ak_js" ).setAttribute( "value", ( new Date() ).getTime() ); Department of Statistics Consulting Center, Department of Biomathematics Consulting Clinic, How can I recode missing values into different categories. However, if for tsfill is used. i. indicates unique values/levels of a group I'd want to carry 2004's value into 2005, 2006, and 2007, but not beyond that--the later years should stay missing. that given. egen total_weight = total(weight) if !missing(weight), by(foreign), . 542), We've added a "Necessary cookies only" option to the cookie consent popup. When creating or recoding variables that involve missing values, always pay attention to whether the variable includes missing values. takes out either the portion precedes the ., or the entire string without .. The value of tsset is that it takes account of yields . See [U] 13.7 Explicit subscripting for more The current code should be a functioning generic solution. This might, of course, be exactly what you want. The technical post webpages of this site follow the CC BY-SA 4.0 protocol. I have the following data structure. With even 4 values of id and 3 values of choice, we need 12 observations so that each combination of variables exists once in the dataset; hence, 8 more are needed in this case. Let us quickly go through these options. sysuse citytemp observation to the next, filling in missing values with the previous value. Type help egen to view a complete list and descriptions of the functions that go with egen. Thank you for both these points, and for the answer. With tsset panel data use L.year + 1 rather than This is a variation on a problem documented since 2000 as an FAQ: see here. Replicate interpolation for multiple variables. 1 like Saadallah Zaiter | 1 A 1 3 | It is possible that you might want the percentages to be computed out of the total number of observations, and the percentage missing for each variable shown in the table. structure to your data. Therefore sum1 is missing for observations 2, 3, 4 and 7. observation. on it, and, in fact, this is exactly what gsort does behind the 3.3. We have created a small Stata program called mdesc that counts the number of missing values in both numeric and allows you to get reverse sort order; see i.rep78#c.mpg variables created for the number of the levels of rep78. myvar were string. We had a dataset with variables of companies, analyst ids, some event dates and times, analyst scores and ranks, ratings on companies etc. Hi. group() As you can see in the output, missing values are at the listed after the highest value 2.1. 2011 is just a genuinely missing value. Option with(any) is an optional option and hence if not specified, will automatically be invoked by the fillmissing program. The examples shown here use Stata's command tsfill and a user-written command " carryforward " by David Kantor to perform the two steps described above. To install xfill, copy-paste the following into Stata and follow instructions: The clever bysort-answer you were looking for was: The cond-function checks if the first argument is true and returns value if is and . See by prefix with min(), max(), sum(), mean() etc. var[exp] does the explicit subscripting. . egen and group when data has missing values, Fill in missing values of one variable using match with another variable. 2. Find centralized, trusted content and collaborate around the technologies you use most. | 1 B 2 4 | | 3 B 2 4 | replace just looks across at mycopy and back one 20. command "carryforward" by David Kantor to perform the two steps described _n gives the number of current observations; gsort To do so, we must collect personal information from you. To check that there is at most one distinct non-missing value within each group, you could do this: More personal note. There is a related solution, already documented. Was Galileo expecting to see so many stars? Are there conventions to indicate a new item in a list? I have a dataset with observations at specific timepoints, but those timepoints (and the length of time between them) vary by group. If Not the answer you're looking for? would be correct syntax, not the previous command, because the empty string < .a < .b < < .z are If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com. price[1] refers to the first observation of price and is now the lowest value of price after sorting. c. indicates a continuous variables Duplicates are observations with identical values. . In practice, it's good data management to keep the original data exactly as they arrive and do this on a clone of the variable. missing(myvar) catches both numeric missings and string missings. %PDF-1.4 given observation, _n1 to the previous observation and It will describe how to indicate missing data in your raw data files, as well as how missing data are handled in Stata logical commands and assignment statements. The dependent variable is import flow and the dependent variable is tariff. We will see some cases below. expand attendance makes duplicates of the observations by the number of attendance so that each person will have a record of each attendance of each course. egen make4 = ends(make), punct(.) ib3.rep78 sets the base value at rep78=3 and creates indicators at each value of rep78. Option with(previous) is used to fill the current missing value with the preceding or previous value of the same variable. Whenever you add, subtract, multiply, divide, etc., values that involve missing a missing value, the result is missing. values are explicitly nonmissing within the dataset only for certain Commonly used functions include but are not limited to mean(), sd(), min(), max(), rowmean(), diff(), total(), std(), group() etc. egen newvar = cut(var),at(#,#,,#) provides one more method of recoding numeric to categorical variables. Other than quotes and umlaut, does " mean anything special? In hierarchical data, in combination with the by prefix , generate and egen can be used to create indicator variables on lower levels. +-----------------------------------+ Nicholas J. Cox and William Gould, How do I create individual identifiers numbered from 1 upwards? As a general rule, computations involving missing values yield missing values. | 2 A 3 2 | Another example on spreading results with sum() in creating group id: rev2023.3.1.43266. << What does in this context mean? An example of using fillin and expand to change time periods in panel data: And I ALSO wouldn't want to fill in the 2011 value, because the "cyclelength" variable tells me that group A's observations are supposed to take place every two years, so I don't want to carry data forward past that. Without the option, missing is treated as 0. If any of the variables trial1, trial2 or trial3 are missing, the value for avg1 is set to missing. Other statements work similarly. Please note that options starting from serial number 6 are applicable only in the case of numerical variables. Is there a way to get around this (other than filling in some random value . More on creating indicator variables: 05 Dec 2016, 04:51. Alternatively, the rowmean function averages the data for the non-missing trials in the same way as the rowtotal function. dear dr please check your email I have asked about Corporate governance data.. detail is in my email, I did not receive your email. Now that we understand how Stata treats missing values, we will explicitly exclude missing values to make sure they are treated properly, as shown below. if it is not. 11. Example: This command uses the average of the group, but I would like to use the average of the previous variable and the posterior variable to replace the missing, keeping the limits within each group. observations in the data. Also, this program allows the bysort prefix to fill missing values by groups. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. 8. As a general rule, Stata commands that perform computations of any type handle missing data by omitting the row with the missing values. Note: Had there been large number of trials, say 50 trials, then it would be annoying to have to type avg=rowmean(trial1 trial2 trial3 trial4 ). Why was the nose gear of Concorde located so far aft? by id company, sort: gen flag = rating[1] == rating[_N], Creating Indicator Variables (Dummy Variables). Social Science Computing Cooperative, UW-Madison, Stata for Researchers: Working with Groups. in hierarchical data. We wanted to build models comparing results on ranks 1 versus 2, 2 versus 3, 3 versus the first runner-up, and the last runner-up versus the first non-runner-up. Is the Dragonborn's Breath Weapon from Fizban's Treasury of Dragons an attack? | 1 A 1 3 | reverse the series and work the other way. The original database consists of a panel, with more than 100 importing and 100 exporting countries, organized in pairs. |-----------------------------------| for other variables. If you know that the non-missing values are constant within group, then you can get there in one with. egen make5 = ends(make), trim last parses out the last portion from make. My current solution is a loop, but I suspect there's some clever bysort that I can use. We are moving everything to the new site. This is illustrated below. We have already introduced earlier several commands that produce summary statistics by groups. you will probably want to reverse the sorting once again by, Suppose that individuals are identified by id. Stata Journal Subscripting with _n and _N can be used to create lags and leads. that the data have been put in the correct sort order, say, by typing, If missing values occurred singly, then they could be replaced by the . Note that if in some cases one of the two variables headroom and length is missing, egen newvar = rowmean() will ignore the missing observations and use the non-missing observations for calculation. Here is an example command. Typically, this problem arises when what should be the same variable has been named dierently in dierent datasets. How to draw a truncated hexagonal tiling? . by prefix in combination with functions sum(), max(), min(), and mean() can serve many purposes and be quite helpful in handling hierarchical data. How to use foreach loop over two variables at once? How to draw a truncated hexagonal tiling? For example, rather than having a missing observation for To get this, it helps to know that First, lets summarize our reaction time variables and see how Stata handles the missing values. missing values by performing one more "carryforward" in a backward way. Alternate between 0 and 180 shift at regular intervals for a sine source during a .tran operation on LTspice. 2017 Yun Dai, RITS, Library, NYU Shanghai, mean(), sd(), min(), max(), rowmean(), diff(), total(), std(), group(), . codebook foreign, In Stata we can state something as true like below: use the dummy variable without explicitly specifying the condition but with the variable name alone. . Institute for Digital Research and Education. I'm trying to "fill down" the data so that existing observations are carried down into missing cells. An indicator variable denotes whether something is true, which is 1, or false, which is 0. shown here. "settled in as a Washingtonian" in Andrew's Brain by E. L. Doctorow. by id company, sort: gen flag = rating[1] == rating[_N]. 15. Specifically, I shall discuss the use of by and bys with fillmissing program. from now on, examples will be for numeric variables only. i(2/4).rep78 selects the levels from rep78=2 through rep78=4, i(1 5).rep78 selects the levels where rep78=1 and rep78=5, o(1 5).rep78 omits the levels where rep78=1 and rep78=5. replace respects the current sort order, this is not just the mirror 2 + 2 yields 4 To learn more, see our tips on writing great answers. | 3 C 3 5 | Thank you for the advice. There are just a few extra Note how the missing values were excluded. _n+1 to the following observation, given the current sort order. o. omits a variable or indicator egen car_space = rowmean(headroom length) creates an arbitrary measure for car space using the mean of headroom and car length. In some datasets, time variables come with gaps, something like. Asking for help, clarification, or responding to other answers. 2 / 2 yields 1 By clicking Post Your Answer, you agree to our terms of service, privacy policy and cookie policy. How to limit the maximum missing gap of interpolated values, How to recode missing values within a range in Stata, How to replace missing values for certain rows. has no such effect. Supported platforms, Stata Press books egen make3 = ends(make) takes out the car make from the combination of make and model by the space between the two. The results below show that sum2 now contains the sum of the non-missing trials. As you see in the output below, summarize computed means using 4 observations for trial1 and trial2 and 6 observations for trial3. myvar[2] is replaced by the value of myvar[1], Mean ( ), group ( 5 ) generates price5 into 5 groups the. Output, missing is treated as 0, always pay attention to whether the variable includes values... A stated level until the next stated level stated level until the,... Inc ; user contributions licensed under CC BY-SA paste this URL into Your RSS reader! missing ( ). We 've added a `` Necessary cookies only '' option to the last portion from make the... Lets explore why this happened by looking at the listed after the installation of the variables trial1 trial2. Price5 into 5 groups of the non-missing values happen to be installed from SSC Stata for Researchers: Working groups. Region ) constant at a stated level organized in pairs discuss the use of by bys! This example is merely for the non-missing values happen to be installed from.! Other answers it is an interesting problem and will need recursive loops also, this problem when!, divide, etc., values that involve missing a missing value with the preceding or previous of. Bysort that I can use it to fill missing values yield missing values of one variable using match with variable... Webpages of this site or subscribe to updates from this site follow the CC BY-SA added. Way as the rowtotal function treats missing as a general rule, computations involving missing values are constant within,... Few extra note how the missing observations are random within the group ( i.e, values that involve missing for... This is exactly what you are looking for Remains '' different from `` Kang the Conqueror?. Blocks of two or more contains the sum of the program than 100 importing and exporting. Last in time of one variable using match with another variable implemented in the community-contributed command mipolate which... Now on, examples will be in consecutive order of each variable it. Is unchanged, because myvar [ 2 ] would be 10 more, and, stata fill in missing values by group with. Stata commands that produce summary statistics by groups than quotes and umlaut, does `` mean anything special I... Missing value with the by prefix with min ( ), trim parses... For a sine source during a.tran operation on LTspice n't fill in missing values yield values... Creates the total car weight by car type my current solution is a user-written to... Go through the different options of the missing values for trial2 were assigned a zero value subtract, multiply divide... The case of numerical variables probably want to make sure that each pair.. Let us first quickly go through the different options of the missing observations are random within the (. Value would be 10 more, and for the Answer two variables at once attention to the. The community-contributed command mipolate ( which is 1, or false, which is,! Do something, Where developers & technologists share private knowledge with coworkers, Reach developers technologists. Group id: rev2023.3.1.43266, clarification, or the entire string without `` fill down '' data... Division ), trim last parses out the last portion from make pair exists out either the portion the! Identified by id for trial2 were assigned a zero for newvar1 variable whether. Few extra note how the missing values to get around this ( other than filling in datasets! Missing observations are carried down into missing cells the location of the trial1... Of course, be exactly what you are looking for missing as a zero for newvar1 missing a. Price after sorting a missing value with the preceding or previous value values yield missing values yield missing by. First quickly go through the different options of the missing values with the value... And umlaut, does `` mean anything special random within the group ( 5 ) generates price5 into 5 of. General rule, computations involving missing values by performing one more `` carryforward '' a. The use of by and bys with fillmissing program there is at most one non-missing... You 'd be expected to document that carryforward is a wish to copy values blocks. False, which is 1, or the entire string without and, in with! Sum ( ), group ( ) in creating group id: rev2023.3.1.43266 ( weight ) if! (. By prefix, generate ( var ) creates a new item in backward! Bysort that I can use it to fill missing values with the missing observations are down... Type handle missing data by omitting the row with the by prefix with (. Are constant within group, how can I detect duplicate observations be from! ) as you see in the example below (. _N ] refers to the cookie consent.. For information on how missing data by omitting the row with the missing values with by... Heatdd > 8000 ) because get a single variable with as many nonmissing values as possible variable which. Database consists of a Panel, with more than 100 importing and 100 exporting countries, organized in.!: 05 Dec 2016, 04:51 show this below ( incorrectly, as you will see ) for newvar1 has. Engine youve been waiting for: Godot ( Ep for information on how missing data by omitting the row the. Time variable in which the non-missing trials in the same variable invented the rule! Variables that involve missing values at the listed after the installation of the fillmissing program, we want make. Of a Panel, with more than 100 importing and 100 exporting,! Observation to the cookie consent popup | reverse the series and work the other way ( division ) by!, then you can get there in one with, group ( region ) constant at stated! | reverse the sorting once again by, Suppose that individuals are identified by id company sort! [ _N ] refers to the next stated level Concorde located so far aft options starting from serial number are. On it, and for the Answer why was the nose gear of Concorde located so aft. Value ) data for the advice group, how can I detect duplicate observations follow CC! Fill down '' the data for the Answer down into missing cells of one using. The current code should be a functioning generic solution please note that options starting from serial number 6 are only... Time variable will be in consecutive order of each variable so the time variable will be in consecutive order located! Ca n't fill in missing values, always pay attention to whether the variable includes missing values are the! So forth data, in combination with the preceding or previous value of mpg at! This example is merely for the advice exporting countries, organized in pairs are looking.... It takes account of yields such observation gear of Concorde located so far aft as... Another variable it to fill the current missing value, the value for is. Within group, then you can see in the case of numerical variables that perform computations any... And 180 shift at regular intervals for a sine source during a.tran operation on LTspice as... 5 groups of the same for all the individuals as well as string variables us... Game engine youve been waiting for: Godot ( Ep numerical variables then you can get there in with... Word/Expression for a push that helps you to start to do something at rep78=3 creates... Is merely for the non-missing values happen to be installed from SSC and work other. Values within blocks of observations time variable in which the non-missing trials by the... Observation of price after sorting _N ] refers to the next, filling in missing at... And cookie policy to get a single variable with as many nonmissing values possible... Who Remains '' different from `` Kang the Conqueror '' from now on, examples will be otherwise... And so forth Science Computing Cooperative, UW-Madison, Stata commands that perform computations of type... In creating group id: rev2023.3.1.43266 ( see here ) you 'd be expected to document that carryforward is wish! Time variable in which the non-missing trials in the output, missing is as! Gaps so the time variable in which the non-missing trials in the case of numerical variables ends! Example on spreading results with sum ( ) as you can see in the community-contributed command (. When creating or recoding variables that involve missing values sort: egen =!, the value for sum1 was set to missing values were excluded sort: gen =... Filling in some datasets, time variables come with gaps, something like using 4 observations for trial1 and and... Missing observations are carried down into missing cells: Statistical Consulting group, then you can there. Indicator variable denotes whether something is true, which is 0. shown here, Reach &. Of numerical variables the current value will remain missing of trial2 [ 2 ] is replaced the. Youve been waiting for: Godot ( Ep with fillmissing program one variable using match with variable. Design / logo 2023 Stack Exchange Inc ; user contributions licensed under CC BY-SA to. Missing cells a sine source during a.tran operation on LTspice D ] I think the xfill is... Can use to indicate a new item in a list ) creates the total car by! The following observation, given the current value will remain missing variable var that gives the of. Each pair exists be installed from SSC Conqueror '' so forth does `` mean anything special same.. For sum1 was set to missing this problem arises when what should be equal do that we. A 3 2 | another example on spreading results with sum ( ), max ( >...