BookmarkSubscribeRSS Feed
valarievil
Obsidian | Level 7

Hello! I have a data set for types of pond ice and their depths. depth is in meters and ice type is either 'multi-year', 'first-year', or 'landfast'.

I need to create two dummy variables where X2=1 if icetype is 'first year', else X2=0 and X3=1 if icetype is 'multi-year', else X2=0. Landfast is irrelevant for this analysis. also X1=depth. Also, Y=broadband_alb (response)

 

Heres the code I tried:

 

 

data ch7hw.prob76;
set problem76;

y=broadband_alb; X1= Depth; if 'icetype' = 'First-Year' then X2=1; else X2=0; if 'icetype' = 'Multi-Year' then X3=1; else X3=0; run; proc reg; model y=X1 X2 X3; run;

But I keep getting errors that say "X1 not found, X2 not found X3 not found..."

 

 

I think I'm just formatting it incorrectly. Please help!

 

Here's a sample of the data:

 

broadband_alb icetype

 

0.62 Landfast
0.64 Landfast
First-Year
First-Year
0.56 First-Year
0.59 First-Year
0.67 First-Year
0.52 First-Year
0.62 First-Year
0.50  Multi-Year
0.49 Multi-Year

 

I would like to add that my data set has many other columns, but these are the only two I'm interested in at the moment.

7 REPLIES 7
novinosrin
Tourmaline | Level 20

is icetype a variable  or constant. Assuming it's a variable, you wouldn't enclose a variable name in quotes. So please remove the quotes. Quotes are only for char values.

 

data ch7hw.prob76;
set problem76;y=broadband_alb;
X1= Depth;
if icetype = 'First-Year' then X2=1; else X2=0;
else if icetype = 'Multi-Year' then X3=1; else X3=0;
run;
valarievil
Obsidian | Level 7

I'm still getting the error "Variable X1, X2, X3 not found" 😞

novinosrin
Tourmaline | Level 20

Please post a sample of your input data

 

In your current sample, I can't see the variable DEPTH

 

DATA have;
input broadband_alb icetype $20.;
cards;
0.62 Landfast
0.64 Landfast
. First-Year
. First-Year
0.56 First-Year
0.59 First-Year
0.67 First-Year
0.52 First-Year
0.62 First-Year
0.50  Multi-Year
0.49 Multi-Year
;
valarievil
Obsidian | Level 7

your right I forgot to add the depth column

 

PaigeMiller
Diamond | Level 26

@valarievil wrote:

I'm still getting the error "Variable X1, X2, X3 not found" 😞


We need to see the ENTIRE log from this program, not just the error messages.

 

Please copy the log as text (not a screen capture) and then paste it here at the SAS Communities into the window that appears when you click on the {i} icon. Do not skip this step.

--
Paige Miller
PaigeMiller
Diamond | Level 26

There are many ways to create dummy variables that are built into SAS, so YOU DON'T HAVE TO DO IT YOURSELF.

 

Many PROCs that do statistical analysis have a CLASS statement, which will create the dummy variables for you. If you do this regression in PROC GLM, the CLASS statement creates the dummy variables for you.

 

If for some reason (which most beginners don't have), you need a data set to contain the dummy variables, there is PROC GLMMOD and also several other methods, as explained in this long thread https://communities.sas.com/t5/SAS-Procedures/How-can-i-create-dummy-variables-How-can-i-change-my-c...

 

--
Paige Miller
PGStats
Opal | Level 21

Unless your homework requires that you use proc reg, you would get better results with less effort with proc glm. Just drop the data step and do:

 

proc glm data=ch7hw.prob76;
class icetype;
model broadband_alb = depth iceType  / solution;
lsmeans iceType / at depth = <some value> pdiff;
run;

The lsmeans statement provides comparisons of mean broadband_alb for different iceType values at a given depth. If you suspect that depth effect might not be the same for different iceType values, add the term iceType*depth to the model.

PG

Ready to join fellow brilliant minds for the SAS Hackathon?

Build your skills. Make connections. Enjoy creative freedom. Maybe change the world. Registration is now open through August 30th. Visit the SAS Hackathon homepage.

Register today!
How to Concatenate Values

Learn how use the CAT functions in SAS to join values from multiple variables into a single value.

Find more tutorials on the SAS Users YouTube channel.

Click image to register for webinarClick image to register for webinar

Classroom Training Available!

Select SAS Training centers are offering in-person courses. View upcoming courses for:

View all other training opportunities.

Discussion stats
  • 7 replies
  • 660 views
  • 1 like
  • 4 in conversation