How to convert strings in a table to numbers?

18 次查看（过去 30 天）
Matthew Gordon
Matthew Gordon 2017-11-10
评论： Matthew Gordon 2017-11-11
I have a large table (280,000 x 40) in which some of the columns are numeric but stored as strings, for example:
Block Lot District
'121' '35' '13'
'121' '36' '13'
'121' '37' '13'
Don't ask me why they are stored this way - the original data is in a .txt file. Is there either
  • a) a way to import this file so that the numbers don't show up as strings (currently I'm using readtable) or
  • b) a way to quickly convert all these entries into numbers. Right now I'm using the following code, which seems to work, but takes a long time:
for i=1:40
b1(:,i)=table2array(bk13(:,i));
b2(:,i)=str2double(b1(:,i));
b3(:,i)=array2table(b2(:,i));
bk13{:,i}=table2cell(b3(:,i));
end

请先登录，再回答此问题。

采纳的回答

Walter Roberson
Walter Roberson 2017-11-11
编辑：Walter Roberson 2017-11-11
It might help to specify the TreatAsEmpty option to readtable, and perhaps the Format option as well.
Using detectImportOptions() and passing the result to readtable() might help.

更多回答（1 个）

Jan
Jan 2017-11-11
A simplification of your code omitting unnecessary steps:
for i=1:40
bk13.(i) = str2double(bk13{:,i});
end

类别

在 Help Center 和 File Exchange 中查找有关 String 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by