The purpose of the GUI is to smooth a given signal. The GUI fetches a variable called ‘y’ from the base workspace. On opening, the variable y is plotted on the axis. When the user slides the slider the smoothed data will be plotted. As the user moves the slide, a P value is changed and the smoothing is improved or worsened depending on the P value and the amount of noise on the variable. On opening the slider value ranges from 0 to 1 and the user can reset the minimum and the maximum value of P. The user can set the GUI to calculate the P value using logarithms. This is done by selecting the logarithmic on the Numeric/Log pop up menu. In this mode the P value is calculated as 10^(-log10(p)) where p is the slider value.

The user can then save the smoothed data by pressing the save button. The name of the saved data will be ‘smoothy’ and this is in a ppform structure. The user can change the name from ‘smoothy’ to any allowable variable name within MATLAB.

Always make sure that the new minimum and maximum value of P are not confusing. i.e min must always be less than max P. In addition, it is good practice to always make sure that the current P is within the new range of P values.