Matlab 4dplot (x,y,z,t)

Matlab 4dplot (x,y,z,t)

我正在尝试绘制包含 x、y、z、t 的数千个数据点的图表。数据位于 .txt 文件中，如下所示：

我正在考虑打开文本文件，创建一个循环来获取 x、y、z、t 并使用 scatter3 进行绘图。如果有人能让我开始了解 MATLAB 代码应该是什么样子，那就太好了。

我不是很明白你想如何在 4D 中绘图，但我猜你想在 3D 中绘图，然后随着时间的推移动态地改变绘图。

但是无论如何，关于文件：

首先，文字阅读非常简单。

  1. 你只需要创建一个变量，即file_text_rd，然后使用这个变量打开文件：

    file_text_rd = fopen('data.txt','r');

    第一个参数为.txt文件的名称（注意需要设置目录为.txt文件所在的文件夹）。第二个参数声明您希望从文本文件中读取。

  2. 然后，您可以从文件中读取数据并将数据放入具有不同功能的变量中（取决于更适合您的）。例如，

    var=fgetl(file_text_rd);

    会将文件内容的第一行放入您的变量中。

    var=fscanf(file_text_rd,%c);

    会将.txt文件的全部内容放入你的变量等，其他读取函数有fread和fgets。因此，根据功能的不同，您可能想使用一些循环函数来为 var 填充内容。

  3. 完成文件读取后，您需要关闭文件：

    fclose(file_text_rd), clear file_text_rd;

下一部分可能有点棘手。这是将读取的字符转换为整数的部分。我为您编写了一些代码，以说明执行此操作的一种方法。在此解决方案中，我使用了 fscanf 函数。

%Open file for reading
file_text_rd=fopen('data.txt','r');
%Read the content (%c means you are reading characters)
var=fscanf(file_text_rd,'%c');
%Converse the characters to double. Have in mind the ascii values of the
%chars, so you can get the actual number value of the numbers in the string
%by subtracting the 48 of the original value, since the zero in ascii is
%numbered as 48 (in decimal system).
conv_var=double(var)-48;
%Define the initial value of your variable (all zeros)
final_var=zeros(1,4);
%Row counter
count_r=1;
%Column counter
count_c=1;
%Divider
times=10;
%Dot flag
dot=0;
%Negative sign flag
negative_sign=0;
%This for loop is for testing every single character from the first to the
%last
for i=1:size(conv_var,2)-1    
    %This if condition is for:
    %1. Checking if the character is a number between 0 and 9
    %2. Checking if the character is a dot
    %3. Checking if the character is a minus sign
    %4. Checking if the character is a comma
    %All other characters are not of interest.
    if (conv_var(i)>=0 && conv_var(i) <=9) || conv_var(i) == -2 || conv_var(i) == -3 || conv_var(i) == -4 

        %If it's not a comma (that means we are still on the last number we
        %were working on) we go in this section
        if conv_var(i)~= -4
            %If it's not a minus sign we go in this section
            if conv_var(i) ~= -3
                %If the dot flag hasn't been set to 1 yet (no dot in the
                %string has yet been found) we don't enter this section
                if dot==1
                    %If the flag HAS been set, then the number just found
                    %on the sequence is divided by 10 and then added to the
                    %old versison, since if we are reading the number
                    %'50.9160', the 9 has to be divided by 10 and then
                    %added to 50
                    final_var(count_r,count_c)=final_var(count_r,count_c)+conv_var(i)/times;
                    %The divider now rizes because the next found number
                    %would be 10 times smaller than the one found just now.
                    %For example, in '50.9160', 1 is 10 times less than 9
                    times=times*10;
                else
                    %This condition is needed so we don't add the ascii
                    %number equivalent to the dot to the number we are
                    %working on.
                    if conv_var(i)~=-2
                        %We multiply the old version of the number we are
                        %working on, since if we are reading the number
                        %'50.9160', first we will read 5, then we will read 0,
                        %so we will need to multiply 5 by 10 and then add the 0
                        %and so on...
                        final_var(count_r,count_c)=final_var(count_r,count_c)*10+conv_var(i);
                    else
                        %If the character found IS the dot, then we just
                        %set the flag
                        dot=1;
                    end
                end
            else
                %If the character found IS the negative_sign, then we set
                %the flag for the negative_sign, so we can multiply the
                %number we are working on atm with -1.
                negative_sign=1;
            end            
        else
            %We get in this section if we found a comma character (or the
            %ascii equvalent of the comma sign, more accurately)
            if negative_sign==1
                %This is the part where we multiply the number by -1 if
                %we've found a minus sign before we found the comma
                final_var(count_r,count_c)=-final_var(count_r,count_c);
            end

            %Here we add 1 to the column counter, since we are ready to
            %work with the next number
            count_c=count_c+1;

            %We reset all the flags and the divider
            dot=0;
            times=10;
            negative_sign=0;
        end

    end

    %The number -38 in ascii is the equivalent of NL, or the end of the
    %line sign (which we can't see), which actually means there was an "Enter" pressed at this point
    if conv_var(i)==-38
        %We set the column counter to one since, we will work now with the
        %first number of the next four parameters
        count_c=1;

        %We increment the row counter so we can start saving the new values
        %in the second row of our matrix
        count_r=count_r+1;

        %We set the next row initially to be all-zeros
        final_var(count_r,:)=zeros(1,4);

        %We reset the flags
        dot=0;
        times=10;
        negative_sign=0;
    end
end

%We close the file, since our work is done (you can put this line after the
%fscanf if you like)
fclose(file_text_rd), clear file_text_rd;

我相信您对如何绘制 4D 数据有所了解，尽管我无法真正理解那部分内容。

希望对您有所帮助， 博扬