<div class="gmail_quote">Hello,</div><div class="gmail_quote"><br></div><div class="gmail_quote">On Tue, Nov 10, 2009 at 1:32 PM, Gökhan Sever <span dir="ltr"><<a href="mailto:gokhansever@gmail.com">gokhansever@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">On Tue, Nov 10, 2009 at 12:09 PM, Darryl Wallace<br>
<div class="im"><<a href="mailto:darryl.wallace@prosensus.ca">darryl.wallace@prosensus.ca</a>> wrote:<br>
</div><div class="im">> Hello again,<br>
> The best way so far that's come to my attention is to use:<br>
> numpy.ma.masked_object<br>
> The problem with this is that it's looking for a specific instance of an<br>
> object. So if the user had some elements of their array that were, for<br>
> example, "randomString" , then it would not be picked up<br>
> e.g.<br>
> ---<br>
> from numpy import *<br>
> mixedArray=array([1,2, '', 3, 4, 'randomString'], dtype=object)<br>
> mixedArrayMask = ma.masked_object(mixedArray, 'randomString').mask<br>
> ---<br>
> then mixedArrayMask will yield:<br>
><br>
> array([ False, False, False, False, False, True])<br>
> Can anyone help me so that all strings are found in the array without having<br>
> to explicitly loop through them in Python?<br>
> Thanks,<br>
> Darryl<br>
<br>
</div>Why not stick to a same Missing-Value-Code or for all the non-valid<br>
data? I don't know how MA module would handle mixed MVCs in a same<br>
array without modifying the existing code. Otherwise looping over the<br>
array an masking the str instances as NaN would be my alternative<br>
solution.<br></blockquote><div><br></div><div>The reason I don't stick to a standard missing value code is because a user may import other things in the datasheet that we need, like row or column labels, or maybe getting data from a specific source which reports missing data as a specific string.</div>
<div><br></div><div>I currently do as you suggested. But when the dataset size becomes large, it gets to be quite slow due to the overhead of python looping.</div><div><br></div><div>Thanks<br></div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div><div></div><div class="h5"><br>
<br>
><br>
> On Fri, Nov 6, 2009 at 3:56 PM, Darryl Wallace <<a href="mailto:darryl.wallace@prosensus.ca">darryl.wallace@prosensus.ca</a>><br>
> wrote:<br>
>><br>
>> What I'm doing is importing some data from excel and sometimes there are<br>
>> strings in the worksheet. Often times a user will use an empty cell or a<br>
>> string to represent data that is missing.<br>
>> e.g.<br>
>> from numpy import *<br>
>> mixedArray=array([1, 2, '', 3, 4, 'String'], dtype=object)<br>
>> Two questions:<br>
>> 1) Is there a quick way to find the elements in the array that are the<br>
>> strings without iterating over each element in the array?<br>
>> or<br>
>> 2) Could I quickly turn it into a masked array of type float where all<br>
>> string elements are set as missing points?<br>
>> I've been struggling with this for a while and can't come across a method<br>
>> that will all me to do it without iterating over each element.<br>
>> Any help or pointers in the right direction would be greatly appreciated.<br>
>> Thanks,<br>
>> Darryl<br>
><br>
><br>
><br>
> --<br>
> ______________________________________<br>
> Darryl Wallace: Project Leader<br>
> ProSensus Inc.<br>
> McMaster Innovation Park<br>
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> Hamilton, Ontario, L8P 0A1<br>
> Canada (GMT -05:00)<br>
><br>
> Tel: 1-905-528-9136<br>
> Fax: 1-905-546-1372<br>
><br>
> Web site: <a href="http://www.prosensus.ca/" target="_blank">http://www.prosensus.ca/</a><br>
> ______________________________________<br>
><br>
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<font color="#888888"><br>
<br>
<br>
--<br>
Gökhan<br>
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</font></blockquote></div><br><br clear="all"><br>-- <br>______________________________________<br>Darryl Wallace: Project Leader<br>ProSensus Inc.<br>McMaster Innovation Park<br>175 Longwood Road South, Suite 301<br>Hamilton, Ontario, L8P 0A1<br>
Canada (GMT -05:00) <br><br>Tel: 1-905-528-9136<br>Fax: 1-905-546-1372<br><br>Web site: <a href="http://www.prosensus.ca/">http://www.prosensus.ca/</a><br>______________________________________<br>