I was confused by your request, because NLIN automatically gives you the 95% confidence intervals for the parameter estimates. Bootstrap gives an alternative approach. But now I think you are requesting a way to program this outside of NLIN, possibly in the same data step used for the R2 calcuation. You know that you can use an ODS output statement to get the parameter estimates and confidence intervals saved as a data file. Then you would have them for other processing. The default method for the confidence interval is
estimate +/- t.SE,
where t is the 97.5 percentile of the t distrubiton with the error degrees of freedom (with large df, t is about 2). Thus, you can check your work.
You can get confidence intervals for the parameters using the BOOTSTRAP command in PROC NLIN.
You can get confidence intervals for the predicted values using the OUTPUT statement in PROC NLIN.
Surely you can look up the BOOTSTRAP command in SAS Help. It's not really that hard to use.
@afgdurrani0 wrote:
But sir(s) I don't have full command over SAS programming as I'm Fisheries specialist. I need you to insert the modify program into my above proc program please.
That's not how this forum works. Your entire program above was written by people on this forum. I question how you can interpret the results if you don't understand how things are calculated. Are you even certain it's doing what you want/need?
If you want someone to write programs for you, hire a consultant. If you want HELP then please feel free to post questions here. Your questions are beyond the help category at this point and more do my work for me.
But how do you know the programmer inputted the correct options to generate said output?
Your original code is from this question, albeit you modified it from the sample provided.
Re: current question - here's the documentation for the bootstrap statement.
Good Luck
"But how do you know the programmer inputted the correct options to generate said output?"
Rhetorical question, I hope.
Not rhetorical at all, PG. Shoot, some days I put gunk into code that I have no idea as to what is going to happen.
I find the structure of your model equation quite strange, with parameter B being used both as an exponent and as a factor... but that is not a SAS issue. Try adding the statement
bootstrap / bootci(BC) bootplots(all);
to proc NLIN to get the confidence intervals. Look at the scatter graph (produced if ods graphics is on) to see the relationship between your parameter estimates.
Sir I didn't get any result. I got this error: ERROR: Procedure BOOTSTRAP not found.
Can't I get the 95% CI like the ones (95% CL, see the attach image) genereted by my proc automatically?
At this point, I can only quote @PaigeMiller "Surely you can look up the BOOTSTRAP command in SAS Help. It's not really that hard to use." and point you to @Reeza's references above.
Ultimately, you will need to show some basic understanding of the statistical procedures you are using to defend your results.
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