This script illustrates an advanced SAS©/Graph technique. It starts by creating a raw data set (`raw_data`) via a DATA step with embedded data (datalines). Then, it uses PROC G3GRID to smooth this data and create an interpolated grid. The smoothed data is then modified to simulate two distinct surfaces. The script configures the graphical environment for HTML output and generates two separate 3D plots with PROC G3D, saving them to a graphics catalog without displaying them immediately. The particularity is to play with the text color (white then black) to avoid a blur effect during superposition. Finally, PROC GREPLAY is used to combine these two graphs into a single image, which is then rendered in the output HTML file.
Data Analysis
Type : INTERNAL_CREATION
Initial data is created directly in the script via a DATA STEP block and the 'datalines' statement. All subsequent data is derived from this internal source.
1 Code Block
DATA STEP Data
Explanation :
This DATA STEP block creates the 'raw_data' table containing X, Y, Z coordinates. The data is embedded directly in the code using the 'datalines' statement.
This DATA STEP block creates the 'raw_data' table containing X, Y, Z coordinates. The data is embedded directly in the code using the 'datalines' statement.
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| 1 | DATA raw_data; |
| 2 | INPUT X Y Z; |
| 3 | DATALINES; |
| 4 | -1.0 -1.0 15.5 |
| 5 | -.5 -1.0 18.6 |
| 6 | .0 -1.0 19.6 |
| 7 | .5 -1.0 18.5 |
| 8 | 1.0 -1.0 15.8 |
| 9 | -1.0 -.5 10.9 |
| 10 | -.5 -.5 14.8 |
| 11 | .0 -.5 16.5 |
| 12 | .5 -.5 14.9 |
| 13 | 1.0 -.5 10.9 |
| 14 | -1.0 .0 9.6 |
| 15 | -.5 .0 14.0 |
| 16 | .0 .0 15.7 |
| 17 | .5 .0 13.9 |
| 18 | 1.0 .0 9.5 |
| 19 | -1.0 .5 11.2 |
| 20 | -.5 .5 14.8 |
| 21 | .0 .5 16.5 |
| 22 | .5 .5 14.9 |
| 23 | 1.0 .5 11.1 |
| 24 | -1.0 1.0 15.8 |
| 25 | -.5 1.0 18.6 |
| 26 | .0 1.0 19.5 |
| 27 | .5 1.0 18.5 |
| 28 | 1.0 1.0 15.8 |
| 29 | ; |
| 30 | RUN; |
2 Code Block
PROC G3GRID Data
Explanation :
The G3GRID procedure is used for interpolation. It takes the raw data ('raw_data') and generates a new 'smoothed' table with a finer grid of points. The 'spline' option with 'smooth=.05' applies a cubic spline smoothing to obtain a regular surface.
The G3GRID procedure is used for interpolation. It takes the raw data ('raw_data') and generates a new 'smoothed' table with a finer grid of points. The 'spline' option with 'smooth=.05' applies a cubic spline smoothing to obtain a regular surface.
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| 1 | PROC G3GRID DATA=raw_data out=smoothed; |
| 2 | grid y*x=z / spline smooth=.05 |
| 3 | axis1=-1 to 1 BY .1 |
| 4 | axis2=-1 to 1 BY .1; |
| 5 | RUN; |
3 Code Block
DATA STEP Data
Explanation :
This DATA STEP modifies the 'smoothed' table to simulate two distinct surfaces. It creates two new variables 'z1' and 'z2' by offsetting the original 'z' value by -8 and +8 respectively.
This DATA STEP modifies the 'smoothed' table to simulate two distinct surfaces. It creates two new variables 'z1' and 'z2' by offsetting the original 'z' value by -8 and +8 respectively.
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| 1 | DATA smoothed; SET smoothed; |
| 2 | label z1='Z' z2='Z'; |
| 3 | z1=z-8; |
| 4 | z2=z+8; |
| 5 | RUN; |
4 Code Block
ODS / GOPTIONS
Explanation :
This block configures the output environment. 'goptions' sets graph parameters (device, size). ODS (Output Delivery System) is configured to close standard listing output and redirect output to an HTML file. The 'nodisplay' option prevents immediate display of graphs.
This block configures the output environment. 'goptions' sets graph parameters (device, size). ODS (Output Delivery System) is configured to close standard listing output and redirect output to an HTML file. The 'nodisplay' option prevents immediate display of graphs.
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| 1 | %let name=example06; |
| 2 | filename odsout '.'; |
| 3 | |
| 4 | goptions device=png; |
| 5 | goptions xpixels=600 ypixels=600; |
| 6 | goptions noborder; |
| 7 | |
| 8 | ODS LISTING CLOSE; |
| 9 | ODS HTML path=odsout body="&name..htm" (title="SAS/Graph g3d plots") style=minimal; |
| 10 | |
| 11 | goptions gunit=pct htitle=4.0 htext=2.5 ftitle="albany amt/bo" ftext="albany amt"; |
| 12 | goptions nodisplay; |
5 Code Block
PROC G3D
Explanation :
The G3D procedure generates the first 3D graph based on the 'z1' variable. 'name="plot1"' saves the graph to the work catalog for later use. The text is set to white to prepare for superposition and avoid visual artifacts.
The G3D procedure generates the first 3D graph based on the 'z1' variable. 'name="plot1"' saves the graph to the work catalog for later use. The text is set to white to prepare for superposition and avoid visual artifacts.
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| 1 | goptions ctext=white; |
| 2 | |
| 3 | title ls=1.5 "Overlay Multiple G3D Surfaces, using Greplay"; |
| 4 | PROC G3D DATA=smoothed; |
| 5 | plot y*x=z1 / |
| 6 | grid zmin=0 zmax=30 xticknum=4 tilt=80 |
| 7 | ctop=purple cbottom=cx00ff00 des='' name="plot1"; |
| 8 | RUN; |
6 Code Block
PROC G3D
Explanation :
The G3D procedure generates the second 3D graph based on the 'z2' variable, using the same axis and angle parameters as the first to ensure perfect alignment. The graph is saved as 'plot2' and the text is set to black.
The G3D procedure generates the second 3D graph based on the 'z2' variable, using the same axis and angle parameters as the first to ensure perfect alignment. The graph is saved as 'plot2' and the text is set to black.
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| 1 | goptions ctext=black; |
| 2 | |
| 3 | PROC G3D DATA=smoothed; |
| 4 | plot y*x=z2 / |
| 5 | grid zmin=0 zmax=30 xticknum=4 tilt=80 |
| 6 | ctop=blue cbottom=red des='' name="plot2"; |
| 7 | RUN; |
7 Code Block
PROC GREPLAY
Explanation :
The 'goptions display' option is re-enabled. The GREPLAY procedure overlays the two graphs ('plot1' and 'plot2') in a single area defined by the 'WHOLE' template. The 'treplay' statement executes this superposition, creating the final composite graph.
The 'goptions display' option is re-enabled. The GREPLAY procedure overlays the two graphs ('plot1' and 'plot2') in a single area defined by the 'WHOLE' template. The 'treplay' statement executes this superposition, creating the final composite graph.
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| 1 | goptions display; |
| 2 | |
| 3 | PROC GREPLAY tc=tempcat nofs igout=work.gseg; |
| 4 | tdef WHOLE des="my template" |
| 5 | 1/llx=0 lly=0 |
| 6 | ulx=0 uly=100 |
| 7 | urx=100 ury=100 |
| 8 | lrx=100 lry=0 |
| 9 | ; |
| 10 | template = whole; |
| 11 | treplay 1:plot1 1:plot2 des='' name="&name"; |
| 12 | RUN; |
| 13 | QUIT; |
8 Code Block
ODS
Explanation :
This block finalizes the process by closing the HTML output file and reactivating the default ODS LISTING destination.
This block finalizes the process by closing the HTML output file and reactivating the default ODS LISTING destination.
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| 1 | ODS HTML CLOSE; |
| 2 | ODS LISTING; |
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