Plotting Time With Matplotlib: Typeerror: An Integer Is Required

G'morning all! Could somebody help me with the following problem? Thank you in advance! I have a CSV file with time-stamps (hours,minutes,seconds,milliseconds) and brightness of an

Solution 1:

The error happens because you are passing strings to datetime.time() which requires integers

If we look at row[0], the result will be "16,59,55,51". So, this string has to be split up using row[0].split(",") which creates a list of strings. The contents of this list needs to be converted to integers using int(), and can then be passed to the datetime.time function.

Your code will become:

x = []
y = []

withopen('calibrated.csv','r') as csvfile:
    plots = csv.reader(csvfile, delimiter=' ')
    forrowin plots:
        hours,minutes,seconds,milliseconds = [int(s) for s inrow[0].split(",")]

        x.append(time(hours,minutes,seconds,milliseconds))
        y.append(float(row[1]))

plt.plot(x,y, marker='o', label='brightness')
plt.gca().invert_yaxis()
plt.xlabel('time [UT]')
plt.ylabel('brightness [mag, CR]')
plt.legend()
plt.grid()
plt.show()

Which gives:

Solution 2:

When you scan in the CSV file your row data contains a string in row[0]. For example, the first line of your csv file becomes:

row = ["16,59,55,51", "13.8"]

To fix this, you need to convert those strings to appropriate values.

withopen('calibrated.csv','r') as csvfile:
        plots = csv.reader(csvfile, delimiter=' ')
        forrowin plots:
            t = [int(x) for x inrow[0].split(',')]
            x.append(time(t[0],t[1],t[2],t[3]))
            y.append(float(row[1])

Another option is to use the datetime stamp like so:

from datetime import datetime
x = []
y = []

withopen('calibrated.csv','r') as csvfile:
    plots = csv.reader(csvfile, delimiter=' ')
    forrowin plots:
        x.append(datetime.strptime(row[0], '%H,%M,%S,%f'))
        y.append(float(row[1]))

This will use your milliseconds as microseconds, but that doesn't seem like it's a very big deal to me. It does, however, allow you to add dates later if you need to.

Solution 3:

Your row[0] is a string of numbers separated by commas, e.g. "16,59,55,51".

You'll need to split them into subfields, and then convert each of the smaller numeric strings to actual integers, e.g.:

(hours, minutes, seconds, microseconds) = [int(v) for v in row[0].split(',')] x.append(time(hours, minutes, seconds, microseconds))