About MigMaster12

MigMaster12 · ‎01-21-2021

Hi there, Thank you for your suggested solutions; the very last 1 you posted worked. However, I do have another do-loop related question that I hope you won't mind taking a look at: if we are using a similar dataset as in this topic, but instead my desired output is where I want to execute a DO function only for the very 1st instance of a "YES" test result: data have; input id session result desired_output; datalines; 1 4 yes 1 1 6 yes 0 1 7 no 0 1 9 yes 0 1 12 . 0 2 1 yes 1 2 2 . 0 2 7 . 0 2 8 yes 0 2 9 yes 0 ; run; I tried both a DO UNTIL(result="no" or result=.) & a DO WHILE(result="yes"), desired_output=1 code, but that doesn't seem to work. Any ideas on how to limit the DO statement to just the 1st instance? Thank you again!

MigMaster12 · ‎01-15-2021

Hello, I have the following hypothetical data scenario: For each id, a diagnosis (value=1) is made after 2 consecutive "YES" hits, which can also be interspersed with missing results in between the 2 consecutive "YES" hits. If that criteria is met, then the diagnosis will be made at the first of the 2 sessions, and the diagnosis will be kept in all subsequent sessions regardless of the results. I was thinking to achieve the diagnosis column I desire, a conditional DO loop with WHERE the first instance of Result="YES" and LAG(Result)="YES" can be used. But to my best knowledge of SAS, there isn't such a kind of DO loop? Only DO WHILE & DO UNTIL? And I'm stuck on how to dealing with the missing values that could be in between the consecutive "YES" hits. Can anyone chime in with suggestions/advice on how to achieve my desired outcome? Thank you!

MigMaster12 · ‎01-13-2021

Greetings, I have a rather peculiar data situation that I am stuck on. I have a list of sample id's that undergoes 2 tests during each session: a RED & BLUE test. The test result values are either 0 (negative) or 1 (positive). To make a diagnosis based on either tests, 2 consecutive positive tests results are required. However, there are sessions where the test results are missing (denoted by "."). It is OK for these "missing" sessions to be in between 2 consecutive positive results. The data looks like: Note that the test diagnosis is currently made at the 2nd consecutive positive result session. Furthermore, after a diagnosis is made, it is kept through the sample's following sessions, until a diagnosis based on a different test is made by the consecutive rule (see ID 2). I would like to update the diagnosis column to where the test diagnosis is made at the 1st of the 2-consecutive-positive-result sessions, as indicated in the last column "desired diagnosis output". How would I go about updating the previous session rows? Thank you for your help!

MigMaster12 · ‎11-20-2020

Greetings, I have a question about the following example dataset of 3 subjects and condition level responses (0, 1, 2) for each visit: Subject visit condition_level A 1 0 A 2 0 A 3 1 B 1 0 B 2 1 B 3 0 B 4 0 C 1 1 C 2 2 C 3 1 What I want to do is specify for all the subjects that they cannot regress on the condition level: i.e. once a person reach 1 or 2, they cannot go back to 0 or 1, and must instead keep the previous level. For the dataset I would like to modify it to the following: Subject visit condition_level A 1 0 A 2 0 A 3 1 B 1 0 B 2 1 B 3 1 B 4 1 C 1 1 C 2 2 C 3 2 I've tried using the lag() function and retain statements, but so far nothing has worked for me. Perhaps an iterative DO loop will be needed? I'd appreciate any help/advice here.

MigMaster12 · ‎11-12-2019

Hello all, I was wondering how to specify the gamma distribution's canonical negative inverse link in the PROC GENMOD procedure. When I tried leaving "LINK" blank, I saw that SAS automatically implemented a POWER(-1) link. However, to my understanding, that is akin to the inverse, and not a negative inverse link. Any help would be greatly appreciated!

MigMaster12 · ‎11-11-2019

Hello all, I have a question regarding the following PROC GENMOD example in the attached screenshot, using a Tweedie distribution & a log link, found in this SAS documentation: http://support.sas.com/kb/60/335.html My question is: how would one go about interpreting the regression beta estimates? Would it be similar to a regression with a log link? For example: CrRuns yields an estimate of 0.0017, and so the interpretation would be something like "1 unit increase in CrRuns results in exp(0.0017) times the outcome variable salary"? Thank you again for your help.

MigMaster12 · ‎11-07-2019

Greetings! I'm running a generalized linear model (GLM) in SAS via PROC GENMOD. I've specified a gamma distribution since my Y response variable is skewed to the right & is non-negative. I've specified a square root power link (since I found that transforming my Y via the square root improves the skewed distribution). I have 2 X predictor variables, X1 and X2. My code looks something like: PROC GENMOD DATA=SAMPLE; MODEL Y = X1 X2 / DIST=GAMMA LINK=POWER(0.5); RUN; SAS gives me an output of the 2 regression estimates for X1 & X2. For example: X1: 0.64 X2: -0.08 How would I go about interpreting these estimates in terms of my Y variable? Can I just say that 1 unit change in X1 results in a increase of 0.64 in Y (assuming that my specific link function has already taken care of the transformation)? Or do I have to take the square of the estimates to obtain the original un-transformed Y? Thank you in advance for your help!

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Re: Conditional "DO WHERE AND UNTIL" loop possible?

Conditional "DO WHERE AND UNTIL" loop possible?

SAS conditionally updating previous row's observation values

Comparing consecutive variable values by group & modifying values

SAS GENMOD: How To Specify A Negative Inverse Link For Gamma Distribut...

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Re: Conditional "DO WHERE AND UNTIL" loop possible?

Re: Conditional "DO WHERE AND UNTIL" loop possible?

Conditional "DO WHERE AND UNTIL" loop possible?

SAS conditionally updating previous row's observation values

Comparing consecutive variable values by group & modifying values

SAS GENMOD: How To Specify A Negative Inverse Link For Gamma Distribut...

Interpreting regression estimates in PROC GENMOD with Tweedie distribu...

PROC GENMOD: How to interpret the beta estimates of a model with a squ...