Hi,
I try to use the proc logistic command in order to obtain the predicted probabilities of each of my variables. Here is the code I am currently using:
proc logistic data=gabarit_final simple alpha=0.05 descending;
class fin_dec
cons (ref="0")
fed (ref="0")
EE (ref="0")
educ_can (ref="0")
/ param=ref;
model fin_dec =
cons
fed
nbr_ess_quali
nbr_multi_crit
EE
educ_can
/link=probit;
output out=pred predicted=p;
run;
quit;
The 'p' variable created gives me the predicted probabilities for each observations in the dataset. However, I would like to estimate the probability by variables instead of by observations. For example, how could I calculate what is the probability of fin_dec = 1 if EE = 1 and the probability of fin_dec = 1 if EE = 0.
Would it be better to use proc qlim or proc probit in order to achieve my goal?
Thank you in advance,
@Shawn08 wrote:
The 'p' variable created gives me the predicted probabilities for each observations in the dataset. However, I would like to estimate the probability by variables instead of by observations. For example, how could I calculate what is the probability of fin_dec = 1 if EE = 1 and the probability of fin_dec = 1 if EE = 0.
If you're including other variables you still need to consider them - typically this would mean setting them to the mean or reference value. I think you can obtain this in PROC LOGISTIC using ESTIMATE statements.
I'm surprised you're not reporting the ODDS RATIOS though, usually in a logistic model, that's what would be of interest.
@Shawn08 wrote:
The 'p' variable created gives me the predicted probabilities for each observations in the dataset. However, I would like to estimate the probability by variables instead of by observations. For example, how could I calculate what is the probability of fin_dec = 1 if EE = 1 and the probability of fin_dec = 1 if EE = 0.
If you're including other variables you still need to consider them - typically this would mean setting them to the mean or reference value. I think you can obtain this in PROC LOGISTIC using ESTIMATE statements.
I'm surprised you're not reporting the ODDS RATIOS though, usually in a logistic model, that's what would be of interest.
Hi,
I would have another question. I'm attemping to manually calculate the predicted value, but I'm unable to do so with the following code:
ods trace on;
ods output ParameterEstimates = estimate;
proc logistic data=gabarit_final simple alpha=0.05 descending outest=out;
class fin_dec
cons (ref="0")
metho_AT (ref="0")
metho_AA (ref="0")
fed (ref="0")
EE (ref="0")
educ_can (ref="0")
multi_crit (ref="0")
/ param=ref;
model fin_dec =
cons
metho_AT
metho_AA
fed
nbr_ess_quali
multi_crit
EE
educ_can
/link=probit technique=newton expb;
output out=pred predicted=p xbeta=xb;
score data=gabarit_final out=estimates2;
run;
ods trace off;
The coefficient I get is the comparison between the 0 and 1 of each variable. However, I am unable to use these in order to manually calculate the predicted value. I know that I don't need to calculate it as it is already given, but I would like to learn how SAS does it in order to understand a bit more how SAS work.
Thank you very much
Also check EFFECTPLOT statement and using ODS OUTPUT to get its result. Calling @Rick_SAS