c_qrsolve - Calculate the least squares solution.

SYNTAX

FUNCTION c_qrsolve (matrix, n_row, n_col, work, result, flag)

     double 			  *matrix;      
     long 			   n_row;        
     long 			   n_col;       
     double 			  *work;
     double 			  *result;     
     long 		           flag;    

PARAMETERS

matrix (input/output, double)

The matrix input should be the QR decompositon matrix returned from c_qrdecomp(). This matrix is used to find the least squares approximation to solve Ax = b for x.

n_row (input, long)

The number of rows in the input matrix.

n_col (input, long)

The number of columns in the input matrix.

work (output, double)

The work vector returned from the c_qrdecomp() routine.

result (input/output, double)

The vector which begins as the b vector in Ax = b. The least squares solution (which is approximately x) is returned.

flag (output, double)

A boolean flag. If FALSE, work on input, contains the results of the c_qrdecomp() routine. If flag is TRUE, the entries in work are reconstructed. Generally, the c_qrdecomp() routine will be used first and FALSE should be passed in.

DESCRIPTION

This routine is used to perform least squares approximation to Ax = b, where A is passed into c_qrdecomp(), and b is result as it is passed into this routine. Result is returned as the least squares solution, and should approximate x.

RETURN VALUE

c_qrsolve() has no return values.

SPECIAL CONSIDERATIONS:

The c_qrsolve() call is for C only.