Matlab中的周末提取 [英] Weekend extraction in Matlab

问题描述

我有一个大小为364 x 5的矩阵"timeVectorDaily".该矩阵具有十进制天形式的数据. 例如

i have a matrix "timeVectorDaily" that is 364 x 5 in size. This matrix has data in form of decimal days. Eg

734870 734870.2 734870.4 734870.6 734870.8
734871 734871.2 734871.4 734871.6 734871.8

依此类推

我只需要从"timeVectorDaily"中提取周末行.我编码以查找是否是周末的方式是使用工作日函数，该函数返回表示星期日至星期六的整数1到7.大小为364 x 1的数组"arrayAllDay"具有此信息. 例如

I need to extract only the weekend rows from "timeVectorDaily". The way i coded to find out if it was a weekend or not is by using the weekday function which returns integers 1 through 7 representing Sunday through Saturday. The array "arrayAllDay" that is 364 x 1 in size has this information. Eg

1
2

等等

我只进入了这个阶段.有人可以帮我从这里开始吗?我需要为每个周末提取1 X 5(工作日函数返回的1或7)

I have only gotten through to this stage.Can someone help me on how to proceed from here? I need to extract the 1 X 5 for every weekend (1 or 7 returned by the weekday function)

j = length(timeVectorDaily);
arrayAllDay = zeros(j,1);
counter = 0;
for m=1:j
    [arrayAllDay(m)] = weekday(timeVectorDaily(m));
    if arrayAllDay(m) == 1
        counter = counter+1;
    elseif arrayAllDay(m) == 7
        counter = counter+1;
    end
end

推荐答案

我们可以通过检查输入到此函数的矩阵的第一列是否输出一个weekday函数中的哪个元素在周末内找到1或7.完成此操作后，这将为我们提供可以从timeVectorDaily中选择的行.

We can find which elements in the weekday function fall on a weekend by checking to see if the first column of your matrix when inputted into this function outputs a 1 or a 7. Once we do this, this will give us which rows we can select out from timeVectorDaily.

事不宜迟:

arrayAllDay = weekday(timeVectorDaily(:,1));
loc = arrayAllDay == 1 | arrayAllDay == 7;
weekendRows = timeVectorDaily(loc,:);

arrayAllDay包含从1到7的数字​​，告诉您该数字在一周的哪一天. loc是一个逻辑数组，其中1表示一天是在周末，而0则不是.最后，weekendRows将包含与周末相对应的所有行.这样，这将生成一个M x 5矩阵，其中M是与矩阵第一列相对应的周末总数.

arrayAllDay contains numbers from 1 to 7 that tell you what day of the week that number falls on. loc is a logical array where 1 denotes that the day falls on a weekend and 0 where it doesn't. Finally, weekendRows will contain all rows that correspond to weekends. As such, this will produce a M x 5 matrix, where M are the total amount of weekends that correspond to the first column of your matrix.

顺便说一句，指的是@Shai，不建议将i和j用作迭代变量，因为这些变量用于表示复数.在此处查看此链接:在Matlab中使用i和j作为变量.这样做会掩盖这些复杂的变量，如果以后再进行任何复杂的分析，则可能会得到不可预测的结果.

BTW, referring to @Shai, it is inadvisable that you use i and j as iteration variables as these are used for representing complex numbers. See this link here: Using i and j as variables in Matlab . Doing so will shadow over these complex variables, and if you do any complex analysis later on, you may get unpredictable results.

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