# helmholtz2Dr2r

This function computes the volume potential V(f) for the Helmholtz equation

Note: function maps column vectors fROI to column vectors uROI.

Note that the factor is added in intOpsFuncs and V is redefined.

## Contents

- See Also
- Code

## See Also

- intOpsFuncs.html

## Code

    function uROI = helmholtz2Dr2r(fROI, seti)

    % fROI = fROI(:);
    % 'helmholtz2Dr2r'
    % size(fROI)
    % size(extendROItoCD(fROI,seti.ROImask))
    % size(fft2(extendROItoCD(fROI,seti.ROImask)))
    % size(reshape(seti.kHat,seti.nCD,seti.nCD))

    uROI = restrictCDtoROI(ifft2(reshape(seti.kHat,seti.nCD,seti.nCD).*fft2(extendROItoCD(fROI,seti.ROImask))),seti.ROImask);
    %uROI = uROI(:);

    % 'uROI'
    % size(uROI)
    end