How can we apply IF/THEN/ELSE statement to each element in a n*m matrix so that the result is also a n*m matrix of TRUE/FALSE?
Could you provide an example?
To get a boolean (0 or 1) matrix, just use a logical expression with a matrix:
proc iml;
x = {1 2,
1 3,
2 4};
b = (x > 2);
print b;
The IF-THEN/ELSE statement works on a scalar quantity. The ANY function and ALL function can be used with the IF-THEN statement to make logical decisions. For example:
if any(x) > 3 then print "Some element > 3";
else print "No element > 3";
if all(x) > 0 then print "All elements > 0";
else print "Some element <= 0";
For more information, see "IF-THEN logic with matrix expressions."
Could you provide an example?
To get a boolean (0 or 1) matrix, just use a logical expression with a matrix:
proc iml;
x = {1 2,
1 3,
2 4};
b = (x > 2);
print b;
The IF-THEN/ELSE statement works on a scalar quantity. The ANY function and ALL function can be used with the IF-THEN statement to make logical decisions. For example:
if any(x) > 3 then print "Some element > 3";
else print "No element > 3";
if all(x) > 0 then print "All elements > 0";
else print "Some element <= 0";
For more information, see "IF-THEN logic with matrix expressions."
Given a matrix x below, I would like to have a resultant matrix y having 1 for each element of x<0 else 0:
proc iml;
x = {1 2,
1 -3,
2 4};
IF x<0 THEN y=1;
ELSE y=0;
print y;
Resultant matrix should be:
y= {0 0,
0 1,
0 0}
The result however is a scalar y=0
As I explained in my previous response, don't use the IF-THEN statement. Just create the binary matrix:
proc iml;
x = {1 2,
1 -3,
2 4};
y = (x<0);
print y;
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