topic Re: Trend line in Gplot in Statistical Procedures

Trend line in Gplot

Sathish_jammy — Mon, 25 Jan 2021 13:23:19 GMT

Hi Experts,

May I know how to create a trend line for the given dataset.

It should be categorized by Regression column following by Hba values

data samp;
input Reg Base_Hba FolHba;
cards;
1 7.8 6.7
2 10.3 7
1 7.9 8.4
1 9.9 9.5
2 10.7 7.8
1 9.5 8
1 11.2 9.6
2 10.3 9.1
1 5.6 5.7
1 5.6 7
1 9	8.8
2 11 8.8
2 15.2 7.8
2 9.1 6.3
run;

/*I have tried the below code but flopped*/
proc gplot data=gp2;
plot Reg*Base_Hba Reg*FolHba/overlay;
run;

Thanks in advance;

Re: Trend line in Gplot

PaigeMiller — Mon, 25 Jan 2021 13:23:29 GMT

This is a very unclear request, but maybe this example is what you want? https://documentation.sas.com/?cdcId=pgmsascdc&cdcVersion=9.4_3.4&docsetId=graphref&docsetTarget=n14ofpm2yqe0mjn1lerq7zbkznu7.htm&locale=en

If not, please explain in more detail, what "Regression column following by Hba values" means.

Also, please consider using the more recent procedure PROC SGPLOT for plotting, it has more features and (usually) a simpler syntax.

Re: Trend line in Gplot

ballardw — Mon, 25 Jan 2021 15:43:01 GMT

"Flopped" is awful vague.

Are there errors in the log?: Post the code and log in a code box opened with the "<>" to maintain formatting of error messages.

No output? Post any log in a code box.

Unexpected output? Provide input data in the form of data step code pasted into a code box, the actual results and the expected results. Instructions here: https://communities.sas.com/t5/SAS-Communities-Library/How-to-create-a-data-step-version-of-your-data-AKA-generate/ta-p/258712 will show how to turn an existing SAS data set into data step code that can be pasted into a forum code box using the "<>" icon or attached as text to show exactly what you have and that we can test code against.

In Proc Gplot when use a plot request like:

plot Reg*Base_Hba Reg*FolHba/overlay;

Reg would be the Y, vertical axis, variable. Is that what you intend?

Most plot options are controlled by SYMBOL statements to indicate connected, smoothed or regessed line values depending on Interpolation options. The default symbol statements are mostly intended for scatter plots.

Which is one reason to consider @PaigeMiller's suggestion because you specify the type of plot up front: Scatter, Series, Regression along with options not possible in Gplot at all.

I am going to guess that maybe something along these lines:

proc Sgplot data=gp2;
  Scatter x=Base_Hba y=FolHba/ group=reg;
run;

If you intend connected lines that would be Series plot with the same syntax. However you likely want to sort your data by Reg and the X axis variable. Otherwise the order of values makes for strange plots.

Re: Trend line in Gplot

PaigeMiller — Mon, 25 Jan 2021 15:53:17 GMT

Also, what exactly do you mean by a "trend line"? Elsewhere you use the word "regression", but a "trend line" and "regression line" don't have to be the same thing.