MATLAB 函数从文本文件中导入数据并计算平均值答案

【问题标题】：MATLAB function to import data from text files and calculate averagesMATLAB 函数从文本文件中导入数据并计算平均值
【发布时间】：2012-02-16 16:58:38
【问题描述】：

我编写了以下将 .txt 文件导入MATLAB 的函数。 .txt 文件可以按小时或 4 分钟间隔记录，根据初始分辨率，脚本将计算每小时或每天的平均值。

function [Daily, Hourly] = calc_avg(pathName)
    TopFolder = pathName;
    dirListing = dir(fullfile(TopFolder,'*.txt'));%#Lists the folders in the directory
                                                  %#specified by pathName.
    for i = 1:length(dirListing);
        fileToRead1{i} = (dirListing(i).name);
        %#lists all of the .txt files in the TopFolder
    end
    cell_all = arrayfun(@(i1)importdata(fullfile(pathName,dirListing(i1).name)),...
        (1:length(dirListing))','un',0); %#'

    %# Apply function to each element of the array.
    d = cat(2,cell_all{:});

    %# Concatenate arrays along each column (i.e. 2).
    %# Find the length of the dataset, which will provide information on the
    %# amount of averaging required.
    if length(d) == 365,...
            error('error: daily averages already calculated'); %#'
    elseif length(d) == 8760;
        daily = squeeze(mean(reshape(d,24,size(d,1)/24,[])));
    elseif length(d) == 131400;
        hourly = squeeze(mean(reshape(d,15,size(d,1)/15,[])));
        daily = squeeze(mean(reshape(d,360,size(d,1)/360,[])));
    end

    %# Find which averages have been calculated:
    A = exist('hourly','var');

    %# If A == 1 means that hourly values had to be calculated therefore
    %# the data if of high resolution (minutes).
    if A == 1;
        hourly = mat2cell(hourly,size(hourly,1),cellfun('size',cell_all,2)).'; %#'
        daily = mat2cell(daily,size(daily,1),cellfun('size',cell_all,2)).'; %#'
    elseif A == 0;
        daily = mat2cell(daily,size(daily,1),cellfun('size',cell_all,2)).';%#'
    end

    %# Create cell in the same format as 'cell_all' where cellfun applies the
    %# same function to each cell in a cell array. 'size' is used to create
    %# the same format.
    for i=1:length(dirListing);
        [~,name{i}] = fileparts(fileToRead1{i});
        %# Obtain the name of each of the .txt files (dirListing)
    end

    %#Generate a structure for the averages calculated.
    if A == 1;
        for i=1:length(dirListing);
            Daily.(genvarname(name{i})) = daily{i};
            Hourly.(genvarname(name{i})) = hourly{i};
        end
    elseif A == 0;
        for i=1:length(dirListing);
            Daily.(genvarname(name{i})) = daily{i};
        end
end

如果我只是将它作为脚本运行，即避免使用该函数，只需在第二行中输入路径名称，该脚本就可以正常工作。但是，一旦我尝试使用 if 作为函数，它就无法工作。它会产生错误：

Error in calc_avg (line 15)
TopFolder = pathName;

我做错了什么？会不会因为pathName是字符串而出现问题？

【问题讨论】：

我假设您在 calc_avg.m 的前 13 行中只有 cmets？
没有错误说明？
是的，第一行是 cmets。出现错误是因为如果 A == 0，则 Hourly 将不存在，因此 matlab 显示错误。我所要做的就是添加 Hourly = [];在最后的循环中。我现在需要做的就是找到一种方法将生成的变量保存到同一目录中。感谢您的帮助。

标签： function matlab

【解决方案1】：

您必须将函数保存在名为 calc_avg.m 的单独文件中（在 MATLAB 路径中的当前文件夹或文件夹中），然后从单独的脚本或命令行中运行它

pathName = 'path/to/file';
[Daily, Hourly] = calc_avg(pathName)

您可能会收到错误，因为您尝试使用 Run (f5) 在编辑器中将函数作为脚本运行。

【讨论】：