Re: [Matplotlib-users] Loding CSV file and plotting histogram of a particular column

[Paul H. <pmh...@gm...>]

Sounds like you want to use pandas, not numpy.

import pandas
import matplotlib.pyplot as plt
df = pandas.read_csv('myfile.txt', sep='\t')
plt.hist(data['A'], bins=30)

...should do it for you.


On Fri, Feb 28, 2014 at 11:06 AM, AR12 <aar...@gm...> wrote:

> Hi,
>
> I have a csv file where head -5 looks like this:
>
> A  B   C
> 100  0.45  0.3
> 67  0.25  0.4
> 50.6  0.2  0.6
> 56.4  0.4  0.3
>
> The columns are tab separated. I want to load this CSV file and plot the
> histogram of the third or second column. I was able to load the csv file
> using this:
> data=csv2rec('Downloads/Sample.txt',delimiter='\t',skiprows=0)
> The file has 2792 rows including the top header row.
>
> When I do
> >> data['A'] I get this error:
> ---------------------------------------------------------------------------
> ValueError                                Traceback (most recent call last)
> <ipython-input-19-856828b8eaa3> in <module>()
> ----> 1 data['A']
>
>
> /Library/Python/2.7/site-packages/numpy-1.9.0.dev_297f54b-py2.7-macosx-10.9-intel.egg/numpy/core/records.pyc
> in __getitem__(self, indx)
>     457
>     458     def __getitem__(self, indx):
> --> 459         obj = ndarray.__getitem__(self, indx)
>     460         if (isinstance(obj, ndarray) and obj.dtype.isbuiltin):
>     461             return obj.view(ndarray)
>
> ValueError: field named A not found
>
> First is data['A'] supposed to read the whole A column? Once I read the
> column I want to be able to plot it. Can I simply do
> >> hist(data['A'],bins=30) or something like that.
>
> Many thanks,
> AR
>
>
>
>
> --
> View this message in context:
> http://matplotlib.1069221.n5.nabble.com/Loding-CSV-file-and-plotting-histogram-of-a-particular-column-tp42938.html
> Sent from the matplotlib - users mailing list archive at Nabble.com.
>
>
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