topic Re: plot a graph for Poisson regression in SAS Programming

plot a graph for Poisson regression

shahd — Tue, 20 Nov 2018 16:47:43 GMT

I wrote this code to Construct a graph of the fitted model versus months. Also to plot the observed number of failures on this graph.

But the code results doesn't show this plot. Can you help with this please

data prog;
input nf month;
datalines;
5 18
3 15
1 14
4 23
0 10
0 5
1 8
0 7
0 12
0 3
1 7
0 2
7 30
0 9
proc genmod data = prog;
model nf= month / dist=Poisson type1 type3 ;
run;
proc logistic data=prog;
model nf=month / aggregate scale=none;
run;
ods graphics on;
proc sort data=prog;by month;run;
proc sgplot data=prog;
title "Problem 3.16.b";
yaxis label="Number of failures";
scatter x=month y=phat / name="points"
legendLabel="number of failures";
series x=month y=nf / name="line"
legendLabel="Predicted number of failures"
lineattrs = GRAPHFIT;
discretelegend "points" "line";
run;
proc genmod plots=all;
model nf = month;
run;
ods graphics off;

Re: plot a graph for Poisson regression

Reeza — Tue, 20 Nov 2018 16:53:46 GMT

You didn't create any output data sets from the PROC GENMOD or LOGISTIC to use to drive those plots. Your PROG data set has no predictions or phat.

Re: plot a graph for Poisson regression

shahd — Tue, 20 Nov 2018 17:30:39 GMT

could you please help me to modify it

Re: plot a graph for Poisson regression

Reeza — Tue, 20 Nov 2018 17:52:54 GMT

Please try adding the OUTPUT statement to your PROC GENMOD and LOGISTIC. If you still can't get it after that attempt, post your code and I'll take a look.

PROC LOGISTIC OUTPUT statement
https://documentation.sas.com/?docsetId=statug&docsetTarget=statug_logistic_syntax27.htm&docsetVersion=14.3&locale=en

PROC GENMOD output statement
https://documentation.sas.com/?docsetId=statug&docsetTarget=statug_genmod_syntax24.htm&docsetVersion=14.3&locale=en

Re: plot a graph for Poisson regression

shahd — Tue, 20 Nov 2018 18:03:28 GMT

still not working

data prog;
input nf month;
datalines;
5 18
3 15
1 14
4 23
0 10
0 5
1 8
0 7
0 12
0 3
1 7
0 2
7 30
0 9
proc genmod data = prog;
model nf= month / dist=Poisson type1 type3 ;
output predicted=p;
run;
ods graphics on;
proc sort data=prog;by month;run;
proc sgplot data=prog;
yaxis label="Number of failures";
scatter x=month y=p / name="points"
legendLabel="number of failures";
series x=month y=nf / name="line"
legendLabel="Predicted number of failures"
lineattrs = GRAPHFIT;
discretelegend "points" "line";
run;
proc genmod plots=all;
model nf = month;
run;
ods graphics off;

Re: plot a graph for Poisson regression

Reeza — Tue, 20 Nov 2018 18:16:47 GMT

You didn't actually create an outputted data set, you need the OUT= portion.

This should get you started then. Your SGPLOT syntax was also wrong so I just simplified it to make it work for now. You can add back the pieces as you get it working. Good Luck.

proc genmod data = prog plots;
model nf= month / dist=Poisson type1 type3 ;
output out=want predicted=p;
run;

proc sgplot data=want;
yaxis label="Number of failures";
scatter x=month y=p / name="points" ;
scatter x=month y=nf / name="line"  ;
run;

@shahd wrote:

still not working

data prog;
input nf month;
datalines;
5 18
3 15
1 14
4 23
0 10
0 5
1 8
0 7
0 12
0 3
1 7
0 2
7 30
0 9
proc genmod data = prog;
model nf= month / dist=Poisson type1 type3 ;
output predicted=p;
run;
ods graphics on;
proc sort data=prog;by month;run;
proc sgplot data=prog;
yaxis label="Number of failures";
scatter x=month y=p / name="points"
legendLabel="number of failures";
series x=month y=nf / name="line"
legendLabel="Predicted number of failures"
lineattrs = GRAPHFIT;
discretelegend "points" "line";
run;
proc genmod plots=all;
model nf = month;
run;
ods graphics off;