Pearson Correlation in SAS - sas

I have a set of data with observations (Joe, Dana, Mark,...) and their respective ratings for a movie ( Batman - 3 Stars, Deadpool - 4 Stars). When I use the proc Corr in SAS only give the correlation between movie and not observations.
How do I find the correlation between the observations in SAS?

I think you should use SPEARMAN option to correlate qualitative data and specify variables to correlate by VAR.
PROC CORR DATA=marks SPEARMAN;
VAR names films ;
RUN;
What have you tried before?

Related

Missing values in VARMAX

I have a dataset with visitors and weather variables. I'm trying to forecast visitors based on the weather variables. Since the dataset only consists of visitors in season there is missing values and gaps for every year. When running proc reg in sas it's all okay but the issue comes when i'm using proc VARMAX. I cannot run the regression due to missing values. How can i tackle this?
proc varmax data=tivoli4 printall plots=forecast(all);
id obs interval=day;
model lvisitors = rain sunshine averagetemp
dfebruary dmarch dmay djune djuly daugust doctober dnovember ddecember
dwednesday dthursday dfriday dsaturday dsunday
d_24Dec2016 d_05Dec2013 d_24Dec2017 d_24Dec2014 d_24Dec2015 d_24Dec2019
d_24Dec2018 d_24Sep2012 d_06Jul2015
d_08feb2019 d_16oct2014 d_15oct2019 d_20oct2016 d_15oct2015 d_22sep2017 d_08jul2015
d_20Sep2019 d_08jul2016 d_16oct2013 d_01aug2012 d_18oct2012 d_23dec2012 d_30nov2013 d_20sep2014 d_17oct2012 d_17jun2014
dFrock2012 dFrock2013 dFrock2014 dFrock2015 dFrock2016 dFrock2017 dFrock2018 dFrock2019
dYear2015 dYear2016 dYear2017
/p=7 q=2 Method=ml dftest;
garch p=1 q=1 form=ccc OUTHT=CONDITIONAL;
restrict
ar(3,1,1)=0, ar(4,1,1)=0, ar(5,1,1)=0,
XL(0,1,13)=0, XL(0,1,14)=0, XL(0,1,13)=0, XL(0,1,27)=0, XL(0,1,38)=0, XL(0,1,42)=0;
output lead=10 out=forecast;
run;
As with any forecast, you will first need to prepare your time-series. You should first run through your data through PROC TIMESERIES to fill-in or impute missing values. The impute choice that is most appropriate is dependent on your variables. The below code will:
Sum lvisitors by day and set missing values to 0
Set missing values of averagetemp to average
Set missing values of rain, sunshine, and your variables starting with d to 0 (assuming these are indicators)
Code:
proc timeseries data=have out=want;
id obs interval = day
setmissing = 0
notsorted
;
var lvisitors / accumulate=total;
crossvar averagetemp / accumulate=none setmissing=average;
crossvar rain sunshine d: / accumulate=none;
run;
Important Time Interval Consideration
Depending on your data, this could bias your error rate and estimates since you always know no one will be around in the off-season. If you have many missing values for off-season data, you will want to remove those rows.
Since PROC VARMAX does not support custom time intervals, you can instead create a simple time identifier. You can alternatively turn this into a format for proc format and converttime_id at the end.
data want;
set have;
time_id+1;
run;
proc varmax data=want;
id time_id interval=day;
...
output lead=10 out=myforecast;
run;
data myforecast;
merge myforecast
want(keep=time_id date)
;
by time_id;
run;
Or, if you made a format:
data myforecast;
set myforecast;
date = put(time_id, timeid.);
drop time_id;
run;

Output the dropped/excluded observation in Proc GLIMMIX - SAS

When I run a proc glimmix in SAS, sometimes it drops observations.
How do I get the set of dropped/excluded observations or maybe the set of included observations so that I can identify the dropped set?
My current Proc GLIMMX code is as follows-
%LET EST=inputf.aarefestimates;
%LET MODEL_VAR3 = age Male Yearc2010 HOSPST
Hx_CTSURG Cardiogenic_Shock COPD MCANCER DIABETES;
data work.refmodel;
set inputf.readmref;
Yearc2010 = YEAR - 2010;
run;
PROC GLIMMIX DATA = work.refmodel NOCLPRINT MAXLMMUPDATE=100;
CLASS hospid HOSPST(ref="xx");
ODS OUTPUT PARAMETERESTIMATES = &est (KEEP=EFFECT ESTIMATE STDERR);
MODEL RADM30 = &MODEL_VAR3 /Dist=b LINK=LOGIT SOLUTION;
XBETA=_XBETA_;
LINP=_LINP_;
RANDOM INTERCEPT/SUBJECT= hospid SOLUTION;
OUTPUT OUT = inputf.aar
PRED(BLUP ILINK)=PREDPROB PRED(NOBLUP ILINK)=EXPPROB;
ID XBETA LINP hospst hospid Visitlink Key RADM30;
NLOPTIONS TECH=NRRIDG;
run;
Thank you in advance!
It drops records with missing values in any variable you're using in the model, in a CLASS, BY, MODEL, RANDOM statement. So you can check for missing among those variables to see what you get. Usually the output data set will also indicate this by not having predictions for the records that are not used.
You can run the code below.
*create fake data;
data heart;set sashelp.heart; ;run;
*Logistic Regression model, ageCHDdiag is missing ;
proc logistic data=heart;
class sex / param=ref;
model status(event='Dead') = ageCHDdiag height weight diastolic;
*generate output data;
output out=want p=pred;
run;
*explicitly flag records as included;
data included;
set want;
if missing(pred) then include='N'; else include='Y';
run;
*check that Y equals total obs included above;
proc freq data=included;
table include;
run;
The output will show:
The LOGISTIC Procedure
Model Information
Data Set WORK.HEART
Response Variable Status
Number of Response Levels 2
Model binary logit
Optimization Technique Fisher's scoring
Number of Observations Read 5209
Number of Observations Used 1446
And then the PROC FREQ will show:
The FREQ Procedure
Cumulative Cumulative
include Frequency Percent Frequency Percent
ƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒƒ
N 3763 72.24 3763 72.24
Y 1446 27.76 5209 100.00
And 1,446 records are included in both of the data sets.
I think I answered my question.
The code line -
OUTPUT OUT = inputf.aar
gives the output of the model. This table includes all the observations used in the proc statement. So I can match the data in this table to my input table and find the observations that get dropped.
#REEZA - I already looked for missing values for all the columns in the data. Was not able to identify the records there are getting dropped by only identifying the no. of records with missing values. Thanks for the suggestion though.

How can I create pivot table in SAS?

I have three columns in a dataset: spend, age_bucket, and multiplier. The data looks something like...
spend age_bucket multiplier
10 18-24 2x
120 18-24 2x
1 35-54 3x
I'd like a dataset with the columns as the age buckets, the rows as the multipliers, and the entries as the sum (or other aggregate function) of the spend column. Is there a proc to do this? Can I accomplish it easily using proc SQL?
There are a few ways to do this.
data have;
input spend age_bucket $ multiplier $;
datalines;
10 18-24 2x
120 18-24 2x
1 35-54 3x
10 35-54 2x
;
proc summary data=have;
var spend;
class age_bucket multiplier;
output out=temp sum=;
run;
First you can use PROC SUMMARY to calculate the aggregation, sum in this case, for the variable in question. The CLASS statement gives you things to sum by. This will calculate the N-Way sums and the output data set will contain them all. Run the code and look at data set temp.
Next you can use PROC TRANSPOSE to pivot the table. We need to use a BY statement so a PROC SORT is necessary. I also filter to the aggregations you care about.
proc sort data=temp(where=(_type_=3));
by multiplier;
run;
proc transpose data=temp out=want(drop=_name_);
by multiplier;
var spend;
id age_bucket;
idlabel age_bucket;
run;
In traditional mode 35-54 is not a valid SAS variable name. SAS will convert your columns to proper names. The label on the variable will retain the original value. Just be aware if you need to reference the variable later, the name has changed to be valid.

SAS boxplot with inner margin

I'm not very experienced in SAS yet.
My problem is that I need to add number of observations to a boxplot (I'm using proc boxplot). I tried insetgroup option, but I don't like the result, I need something prettier.
I have found this
http://support.sas.com/resources/papers/wusspaper.pdf
I need something like this, with numbers in the inner margin
It's great they have code there, but I don't get where are these numbers (No. of subjects at visit) are taken from, if they are calculated separately, where they are in a dataset, etc. It's a pity the initial dataset is not shown.
Any help and any other ideas how to add numbers of patients will be very appreciated.
Below is some SAS code where the Ns are added to proc boxplot using annotate. In general for annotate, you need to be careful about setting up the coordinate system you want, read the documentation regarding annotate and xsys/ysys for a detailed explaination.
Hope this helps.
proc sort data=sashelp.class out=work.class;
by sex;
run;
*** GET COUNTS FOR EACH GROUP ***;
proc freq data=class;
tables sex / out=stats;
run;
*** CREATE ANNOTATE DATASET ***;
data anno_stats;
set stats (drop=percent);
xsys='2';
ysys='1';
position='5';
function='label';
text='N=' || strip( put(count, 3.));
*** X COORDINATE IS THE GROUP VARIBLE IN THE BOXPLOT ***;
*** USE VARIABLE XC INSTEAD OF X SINCE THIS IS A CHARACTER VARIABLE IN THIS EXAMPLE ***;
xc=sex;
*** Y COORDIANTE IS 3% ABOVE X-AXIS, BASED ON YSYS=1 ***;
y=3;
run;
proc boxplot data=class anno=anno_stats;
plot height * sex;
run;

Contingency table in SAS

I have data on exam results for 2 years for a number of students. I have a column with the year, the students name and the mark. Some students don't appear in year 2 because they don't sit any exams in the second year. I want to show whether the performance of students persists or whether there's any pattern in their subsequent performance. I can split the data into two halves of equal size to account for the 'first-half' and 'second-half' marks. I can also split the first half into quintiles according to the exam results using 'proc rank'
I know the output I want is a 5 X 5 table that has the original 5 quintiles on one axis and the 5 subsequent quintiles plus a 'dropped out' category as well, so a 5 x 6 matrix. There will obviously be around 20% of the total number of students in each quintile in the first exam, and if there's no relationship there should be 16.67% in each of the 6 susequent categories. But I don't know how to proceed to show whether this is the case of not with this data.
How can I go about doing this in SAS, please? Could someone point me towards a good tutorial that would show how to set this up? I've been searching for terms like 'performance persistence' etc, but to no avail. . .
I've been proceeding like this to set up my dataset. I've added a column with 0 or 1 for the first or second half of the data using the first procedure below. I've also added a column with the quintile rank in terms of marks for all the students. But I think I've gone about this the wrong way. Shoudn't I be dividing the data into quintiles in each half, rather than across the whole two periods?
Proc rank groups=2;
var yearquarter;
ranks ExamRank;
run;
Proc rank groups=5;
var percentageResult;
ranks PerformanceRank;
run;
Thanks in advance.
Why are you dividing the data into quintiles?
I would leave the scores as they are, then make a scatterplot with
PROC SGPLOT data = dataset;
x = year1;
y = year2;
loess x = year1 y = year2;
run;
Here's a fairly basic example of the simple tabulation. I transpose your quintile data and then make a table. Here there is basically no relationship, except that I only allow a 5% DNF so you have more like 19% 19% 19% 19% 19% 5%.
data have;
do i = 1 to 10000;
do year = 1 to 2;
if year=2 and ranuni(7) < 0.05 then call missing(quintile);
else quintile = ceil(5*ranuni(7));
output;
end;
end;
run;
proc transpose data=have prefix=year out=have_t;
by i;
var quintile;
id year;
run;
proc tabulate data=have_t missing;
class year1 year2;
tables year1,year2*rowpctn;
run;
PROC CORRESP might be helpful for the analysis, though it doesn't look like it exactly does what you want.
proc corresp data=have_t outc=want outf=want2 missing;
tables year1,year2;
run;