The prototype software was modified to count stress sin2ψ method based on the geometric center of gravity of the peaks. Based on data smoothed fitted linear background, which then is subtracted from the raw data and the smoothed data, which served to match one of the specified distribution function. For now uses Gaussian distributions, Cauchy, Lorentz and Pearson VII. It is expected to use a combination of the distributions of typical peaks, such as the separated components of Kα and Kβ. Distributions were determined on the basis of the measured peak ends, and this was done in several ways. In the first stage background was subtracted and counted three ranges: standard deviation, maximum width of the peak intensity and the full range of data best suited for distribution. In the second stage, left background, and counted two ranges: the standard deviation and the maximum width of the peak intensity for the best-matched schedule. Calculated by these methods zwłascza principal stresses and principal stress angle of incidence showed a fairly significant differences.