Re: reading csv data with missing values

Done. See example 5. THX

On 2/28/14, 2:52 PM, Dave Allured - NOAA Affiliate wrote:
> All,
>
> A new function str_split_csv (6.1.0) has made it easy to correctly read CSV
> files with empty fields as missing values. Try this program with the test
> file attached to Zhang's original message:
>
> begin
> infile = "test-with-missing.csv"
> read_whole_file = -1
> lines = asciiread (infile, read_whole_file, "string")
> opt_quoting = 0
> strs = str_split_csv (lines, ",", opt_quoting)
> nums = tofloat (strs)
> print (strs + " " + nums)
> end
>
> CSV files with blank cells are very common in "the real world". Please
> consider adding this simple demo to the NCL examples page for "Reading CSV
> files". Thank you. Thanks also to the NCL team for adding str_split_csv,
> very useful.
>
> --Dave
>
> On Wed, Feb 26, 2014 at 9:17 PM, Will Hobbs <Will.Hobbs@utas.edu.au> wrote:
>
>> Bin
>>
>> The reason that NCL doesn't recognise the missing data is that those
>> entries are completely blank; you need something in there or NCL won't be
>> able to recognise those blank spaces as missing values.
>>
>> Try putting a FillValue in the blank fields; this can be any value that
>> is outside the physical range of you input data, although -999.9 is the NCL
>> default.
>> Then, assign the FillValue as an attribute after you have read the csv
>>
>> >data = asciiread("data/test.csv",(/16,2/),"float")
>>> data@_FillValue = -999.9 ;(or whatever number you have assigned in the
>> input .csv file
>>
>> Hope that helps
>>
>> Will
>>
>> From: zhangbinrc <zhangbinrc@163.com>
>> Date: Thursday, 27 February 2014 2:59 PM
>> To: "ncl-talk@ucar.edu" <ncl-talk@ucar.edu>
>> Subject: [ncl-talk] reading csv data with missing values
>>
>> Hi all,
>>
>> I’m writing a script to read in a 16x2 csv file with 3 values missing. The
>> main script lines are as following:
>>
>> data = asciiread("data/test.csv",(/16,2/),"float")
>>
>> print(data(:,1))
>>
>> The problem is that the missing values are skipped. Is there any way that
>> I can keep the missing values in the right location of the matrix ?
>>
>> The file is attached here.
>>
>> Thanks!
>>
>> 张斌 博士生/Bin Zhang Ph.D. Candidate
>> 清华大学地球系统科学研究中心/ Center for Earth System Science, Tsinghua
>> Email:zhangbin06@mails.tsinghua.edu.cn
>>
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>
>
>
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Received on Mon Mar 3 08:31:43 2014