# How to convert a matrix of double to int?

2,004 次查看（过去 30 天）
Emilie Mussard2013-12-5

I need to convert my matrix [648x2400 double] into integers value to use a mRMR function, but I do not know how to do that. I have tried to convert by uint8(matrix) or int8(matrix) but it does not give integers... And I always have this note: "Undefined function 'mrmr_mid_d' for input arguments of type 'int8' " (or double, or uint, and so on) can someone help me? thank you
##### 1 个评论显示 无隐藏 无
Nguyen Phuong 2019-9-11
img_d = double(img);
imshow(img_d/255);

### 采纳的回答

Wayne King 2013-12-5

I'm not sure what you are saying. Do you mean that:
X = 10+randn(16,16);
X = uint8(X);
Does not result in integers for the output in X?
The error message you report ("Undefined function 'mrmr_mid_d' for input arguments of type 'int8' ") just sounds like MATLAB cannot recognize the function, mrmr_mid_d.m.
You need to add the folder containing that function to the MATLAB path. You can launch
>>pathtool
to add that folder.
##### 1 个评论显示 无隐藏 无
Emilie Mussard 2013-12-5
Thank you, I hadn't thought of the path problem and I focused on a wrong problem!

### 更多回答（3 个）

Kelly Kearney 2013-12-5
It's possible that mrmr_mid_d.m isn't on your path; the other possibility is that it doesn't actually accept integer data types as input, but integer values stored as double arrays. In this case, you need to round your data in some manner (see round, ceil, floor, fix, etc)
x = rand(10)*10;
x = round(x);
mrmr_mid_d(x); % or whatever the syntax is...
##### 0 个评论显示 -1更早的评论隐藏 -1更早的评论

To convert an array of type “double” to an integer type, you can use a function such as “int64”, which converts the input to a 64-bit integer. For example, consider the following:
x_double = [1 2 3];
x_int = int64(x)
For more information on integer types and functions, see https://www.mathworks.com/help/matlab/matlab_prog/integers.html
##### 0 个评论显示 -1更早的评论隐藏 -1更早的评论

sixwwwwww 2013-12-5
you can do it as follow:
a = randi(100, 4);
a = int64(a);
see following link for more information about integer data types:
##### 2 个评论显示 1更早的评论隐藏 1更早的评论
Munawara Munia 2016-4-26
Hi Emilie, I am facing the same problem. I ama also trying to use mRMR and getting the same errors. Could you kindly tell me what was the issues with your code and how you solved it..?? Badly need a solution about it. Thanks in advance. :)

### 类别

Find more on Resizing and Reshaping Matrices in Help Center and File Exchange

### Community Treasure Hunt

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

Start Hunting!

Translated by