CODEWITHSUNDEEP
pythonpandasmatplotlibpython-3.7
Bipt
Bipt

Reputation: 1

How to I solve a ValueError: the truth value

I have a data file from which columns of data are selected using pandas. I then use the data from these column to plot it on a scatter graph using matplotlib but i get an error which says: ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().

I have searched this problem already on StackOverflow but they don't relate to data plotting

# Getting data from column that user selects
variable1 = location_data.iloc[0:-1, columnPosition1]
variable2 = location_data.iloc[0:-1, columnPosition2]

# Converting data from variable1 and 2 to float and storing in list called x & y
for xValue in variable1:
    x.append(float(xValue))

for yValue in variable2:
    y.append(float(yValue))


# x and y are lists which hold data from excel file
# Error begins here
plt.scatter(x, y, marker='o')
plt.xlabel(variable1, fontsize = 15)
plt.ylabel(variable2, fontsize = 15)
plt.title('A graph of ' + variable1 + ' and ' + variable2)

Traceback (most recent call last):
  File "F:\Computer Science\NEA\Code\Coursework.py", line 115, in <module>
    plot_data(variable1, variable2)
  File "F:\Computer Science\NEA\Code\Coursework.py", line 96, in plot_data
    plt.xlabel(variable1, fontsize = 15)
  File "C:\Users\Naima\AppData\Local\Programs\Python\Python37-32\lib\site-packages\matplotlib\pyplot.py", line 3065, in xlabel
    xlabel, fontdict=fontdict, labelpad=labelpad, **kwargs)
  File "C:\Users\Naima\AppData\Local\Programs\Python\Python37-32\lib\site-packages\matplotlib\axes\_axes.py", line 265, in set_xlabel
    return self.xaxis.set_label_text(xlabel, fontdict, **kwargs)
  File "C:\Users\Naima\AppData\Local\Programs\Python\Python37-32\lib\site-packages\matplotlib\axis.py", line 1564, in set_label_text
    self.label.set_text(label)
  File "C:\Users\Naima\AppData\Local\Programs\Python\Python37-32\lib\site-packages\matplotlib\text.py", line 1191, in set_text
    if s != self._text:
  File "C:\Users\Naima\AppData\Local\Programs\Python\Python37-32\lib\site-packages\pandas\core\generic.py", line 1478, in __nonzero__
    .format(self.__class__.__name__))
ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().

Upvotes: 0

Views: 1697

Answers (1)

MisterMiyagi
MisterMiyagi

Reputation: 50116

You are setting your data series as the label string:

plt.xlabel(variable1, fontsize = 15)

Since plt.xlabel and plt.ylabel do not check the type of the label, they chokes when trying to treat your series as a string.

Set an explicit string as the label instead:

plt.xlabel("The X Axis", fontsize = 15)

Upvotes: 0

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