/**
* return a matrix
*
* @param operands[0] = number of rows
* @param operands[1] = number of columns
*/
public OperandToken evaluate(Token[] operands) {
// at least one operand
if (getNArgIn(operands) < 1) throwMathLibException("ones: number of arguments <1 ");
// number of arguments
int n = getNArgIn(operands);
// set up dimension array
int[] dim = new int[n];
// only DoubleNumberTokens accepted
// each token is one dimension
for (int i = 0; i < n; i++) {
if (!(operands[i] instanceof DoubleNumberToken))
throwMathLibException("ones: arguments must be numbers");
// get requested dimension
dim[i] = (int) ((DoubleNumberToken) operands[i]).getValueRe();
if (dim[i] < 0) throwMathLibException("ones: dimension <0");
}
// special case for rand(k) -> rand(k,k)
if (dim.length == 1) {
int d = dim[0];
dim = new int[] {d, d};
}
// ceate array of correct size with dimensions "dim"
DoubleNumberToken num = new DoubleNumberToken(dim, null, null);
// create "1" value for all values of num
for (int i = 0; i < num.getNumberOfElements(); i++) {
num.setValue(i, 1, 0);
}
return num;
} // end eval
