CODEWITHSUNDEEP
pythonmatplotlib
Peter Chao
Peter Chao

Reputation: 443

how to label x-axis using python matplotlib

I am trying to make a graph from my csv data file. My code is as follow:

for name in per_data.dtype.names[2:]:
    plt.plot(per_data['RELEASE'],per_data[name],label=name)
    plt.legend(loc='upper left',prop = {'size':7},bbox_to_anchor=(1,1))
    plt.tight_layout(pad=5)
    plt.xlabel ('Release')
    plt.ylabel ('Time/Sec')
    plt.title ('Ingest Performance Test')
    plt.grid()
    plt.show()

enter image description here

my csv data is:

DATE    RELEASE 10GB    100GB   200GB   400GB   600GB   800GB   1000GB
5/5/16  2.67    0.36    4.18    8.54    18      27      38      46
5/5/16  2.68    0.5     4.24    9.24    18      27      37      46
5/6/16  2.69    0.32    4.3     9.18    19      29      37      46
5/6/16  2.7     0.35    4.3     9.3     19      28      37      46
5/6/16  2.71    0.3     4.18    8.18    16      24      33      41

as you can see, I am using the 2nd column -- RELEASE as my x-axis label. The issue is: the actual release numbers are: 2.67, 2.68, 2.69 ,2.70, 2.71 However, in the graph the program added extra point (2.65, 2.75, 2.85, 2.95, and 2.705). How do I set it so the label of x-axis will reflect my release number?

Upvotes: 2

Views: 33274

Answers (1)

user6764549
user6764549

Reputation:

You need to use plt.xticks() as shown here. It controls what ticks and labels to use for your x-axis.

In your example, you will have to add another line as shown below:

for name in per_data.dtype.names[2:]:
    plt.plot(per_data['RELEASE'],per_data[name],label=name)
    plt.legend(loc='upper left',prop = {'size':7},bbox_to_anchor=(1,1))
    plt.tight_layout(pad=5)
    plt.xlabel ('Release')
    plt.xticks (per_data['RELEASE'])
    plt.ylabel ('Time/Sec')
    plt.title ('Ingest Performance Test')
    plt.grid()
    plt.show()

Upvotes: 8

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