Converting pixel coordinates from vertical chart to horizontal chart

Question

I am trying to get the pixel coordinates from each datapoint after I have converted the chart to a horizontal position. Attached is what I am using to get vertical coordinate data:

import numpy as np
import matplotlib.pyplot as plt 

def pixelCoords(x_labels, y_values):
    coordList = []
    x_vals = []
    i = 1
    fig, ax = plt.subplots()
    for item in x_labels:
        x_vals.append(i)
        i+=1
    points, = ax.plot(x_vals, y_values)
    x, y = points.get_data()
    ax.get_xbound()
    xy_pixels = ax.transData.transform(np.vstack([x,y]).T)
    xpix, ypix = xy_pixels.T
    for xp, yp in zip(xpix, ypix):
        coordList.append((round(xp, 2), round(yp, 2)))
    plt.clf()
    plt.close()
    return coordList


x_labels = ['x1','x2','x3']
y_values = [30,40,50]

coordValues = pixelCoords(x_labels, y_values)

However I cannot seem to figure out how to get the coordinates for horizontal, I assume there is probably a simple formula to go from [xV, yV] to [xH, yH] but I cannot figure it out. Thanks!

Answer 1

I think this simple formula solves it correctly, if anyone sees an error please tell me, thanks! I simply use the same function but pass coordValues through the following loop:

for item in coordValues:
    item[0] = round(((item[1]/480) * 640), 2)
    item[1] = round((480 - ((item[0]/640) * 480)), 2)