["python","matplotlib","xticks","yticks"]
How to force integer tick labels

My python script uses matplotlib to plot a 2D "heat map" of an x, y, z dataset. My x- and y-values represent amino acid residues in a protein and can therefore only be integers. When I zoom into the plot, it looks like this: As I said, float values on the x-y axes do not make sense with my data and I therefore want it to look like this: Any ideas how to achieve this? This is the code that generates the plot: def plotDistanceMap(self): # Read on x,y,z x = self.currentGraph['xData'] y = self.currentGraph['yData'] X, Y = numpy.meshgrid(x, y) Z = self.currentGraph['zData'] # Define colormap cmap = colors.ListedColormap(['blue', 'green', 'orange', 'red']) cmap.set_under('white') cmap.set_over('white') bounds = [1,15,50,80,100] norm = colors.BoundaryNorm(bounds, cmap.N) # Draw surface plot img = self.axes.pcolor(X, Y, Z, cmap=cmap, norm=norm) self.axes.set_xlim(x.min(), x.max()) self.axes.set_ylim(y.min(), y.max()) self.axes.set_xlabel(self.currentGraph['xTitle']) self.axes.set_ylabel(self.currentGraph['yTitle']) # Cosmetics #matplotlib.rcParams.update({'font.size': 12}) xminorLocator = MultipleLocator(10) yminorLocator = MultipleLocator(10) self.axes.xaxis.set_minor_locator(xminorLocator) self.axes.yaxis.set_minor_locator(yminorLocator) self.axes.tick_params(direction='out', length=6, width=1) self.axes.tick_params(which='minor', direction='out', length=3, width=1) self.axes.xaxis.labelpad = 15 self.axes.yaxis.labelpad = 15 # Draw colorbar colorbar = self.figure.colorbar(img, boundaries = [0,1,15,50,80,100], spacing = 'proportional', ticks = [15,50,80,100], extend = 'both') colorbar.ax.set_xlabel('Angstrom') colorbar.ax.xaxis.set_label_position('top') colorbar.ax.xaxis.labelpad = 20 self.figure.tight_layout() self.canvas.draw()
This should be simpler: (from https://scivision.co/matplotlib-force-integer-labeling-of-axis/) import matplotlib.pyplot as plt from matplotlib.ticker import MaxNLocator #... ax = plt.figure().gca() #... ax.xaxis.set_major_locator(MaxNLocator(integer=True)) Read the official docs: https://matplotlib.org/stable/api/ticker_api.html#matplotlib.ticker.MaxNLocator