matrixbase::IFFTShift

IFFTShift

1 Description
2 Syntax
3 Parameters
4 Return
5 Examples
6 Remark
7 See Also
8 header to Include

Description

Inverse FFTShift.

Syntax

int IFFTShift( matrixbase & mbShifted, int nDim = -1 )

Parameters

mbShifted: [output] The output matrix in which the un-shifted matrix is returned
nDim: [input] Inverse FFTShifts can occur row wise (relative to the first dimension when nDim=1), column wise (relative to the second dimension when nDim=2), or relative to both or the first dimension and then the second dimension (when nDim=-1 default)

Return

Returns 0 on success and a non-zero error code on failure:

-1=nDim is not -1, 1, or 2

-2=Internal casting error

Examples

EX1

void matrixbase_IFFTShift_ex1()
{ 
    matrix mSource = {
        {1,2,3},
        {4,5,6},
        {7,8,9}
    };
    int rc = mSource.IFFTShift( mSource );
    if(rc!=0) 
        printf("Error: IFFTShift failed. rc=%d\n", rc); 
    else{
        printf("The matrix is:\n");
        for(int ii=0; ii< mSource.GetNumRows(); ii++){
            for(int jj=0; jj< mSource.GetNumCols(); jj++) 
                printf("%g  ", mSource[ii][jj]);
            printf("\r\n");
        }
    }
}

EX2

// Inverse-shifting matrix rows or columns
void matrixbase_IFFTShift_ex2()
{
    matrix mSource = {
        {1,2,3},
        {4,5,6},
        {7,8,9}
    };
    matrix mShifted, mIShifted;
    int ii, jj;
 
    MatrixPage MatPg1;
    MatPg1.Create("Origin");
    MatrixLayer MatLy1 = MatPg1.Layers(0);
    Matrix Mat1(MatLy1);
 
    Mat1 = mSource;
    printf("  The original matrix is %s.\n",Mat1.GetName());
    
    MatrixPage MatPg2;
    MatPg2.Create("Origin");
    MatrixLayer MatLy2 = MatPg2.Layers(0);
    Matrix Mat2(MatLy2);
  
    int rc=mSource.FFTShift(mShifted);    
    if(rc!=0) 
        printf("  Error: FFTShift failed.\n");
    else {
        Mat2 = mShifted;
        printf("  %s is a shifted matrix relative to both 1st and 2nd dimensions.\n",Mat2.GetName());
    }

    MatrixPage MatPg3;
    MatPg3.Create("Origin");
    MatrixLayer MatLy3 = MatPg3.Layers(0);
    Matrix Mat3(MatLy3);
    rc=mShifted.IFFTShift(mIShifted);   
    
    if(rc!=0) 
        printf("  Error: IFFTShift failed.\n");
    else {
        Mat3 = mIShifted;
        printf("  %s is the invert-sfifted matrix from %s, made the original recovered.\n",Mat3.GetName(),Mat2.GetName());
    }
}

Remark

Inverse FFTShift. Inverse FFTShifts can occur row wise or relative to the first dimension (nDim=1), column wise or relative to the second dimension(nDim=2), or relative to both or the first dimension and then the second dimension (nDim=-1 default). The result matrix and this matrix can be the same (i.e m1.IFFTShift(m1);).