Element-wise square of a matrix in EMGU CV - emgucv

Question

I need the element-wise square of a matrix. In Matlab I find this code:
if A is matrix then A.^2 calculates the element wise square of the matrix. Is there any function in Emgu Cv that does the same?
Actually I need standard deviation of a matrix. If there a function of computing standard deviation of method for computing standard deviation then it will more helpful for me.

Answer 1

Element-wise square is the same as element-wise multiplication with the matrix itself. So, the following code line should do the trick (assuming the Matrix is called mat):
mat._Mul(mat);
Be aware though that this replaces the original mat. If you want to have it saved, you can do:
Matrix<byte> squaredMatrix = mat.Copy();
squaredMatrix._Mul(mat);

Answer 2

If you want the standard deviation, then the Image class provides a method AvgSdv that wraps the OpenCV equivalent function cvAvgSdv. Maybe you can do this by copying your Matrix to an Image first.
Implementation copied below for information:
/// <summary>
/// Calculates the average value and standard deviation of array elements, independently for each channel
/// </summary>
/// <param name="average">The avg color</param>
/// <param name="sdv">The standard deviation for each channel</param>
/// <param name="mask">The operation mask</param>
public void AvgSdv(out TColor average, out MCvScalar sdv, Image<Gray, Byte> mask)
{
average = new TColor();
MCvScalar avgScalar = new MCvScalar();
sdv = new MCvScalar();
CvInvoke.cvAvgSdv(Ptr, ref avgScalar, ref sdv, mask == null ? IntPtr.Zero : mask.Ptr);
average.MCvScalar = avgScalar;
}

Answer 3

If your data is an image rather than a matrix, you can use Image(TColor, TDepth).Mul Method:
http://www.emgu.com/wiki/files/2.3.0/document/html/01b9ba23-0058-3167-16ee-206a4befd7f3.htm
Here is the code:
Iamge.Mul(Iamge, 1);
For standard deviation of a matrix，try Image(TColor, TDepth).AvgSdv Method.