Matlab 4dplot（x，y，z，t）

Question

我想绘制包含x，y，z，t的数千个数据点的图形。的数据是在一个.txt文件和如下所示：

• [X，Y，Z，时间]
• [50.9160，12.2937，-44.9963，0.0]
• [50.9160，12.2937， - 44.9963，0.8]
• [50.9160，12.2937，-44.9963，1.8]
• [50.9160，12.2937，-44.9963，2.8]
• [50.9160，12.2937，-44.9963，3.8]
• [50.9160，12.2937 ，-44.9963，4.9]
• [50.9160，12.2937，-44.9963，8.8]
• [50.9160，12.2937，-44.9963，11.1]
• [50.9160，12.2937，-44.9963，11.7]
• [50.9160，12.2937，-44.9963，12.8 ]
• [50.8989，12.3248，-45.0376，13.7]
• [50.8989，12.3248，-45.0376，14.9]
• [50.8989，12.3248，-45.0376，15.7]
• [50.8989，12.3248，-45.0376 ，17.2]
• [50。 8989，12.3248，-45.0376，17.7]
• 等（超过一千个数据点）

我一起打开文本文件的行思，创建一个循环，将抢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，那很好。

Answer 1

我真的不明白你想如何在4D中进行绘图，但我猜你希望以3D绘图，随着时间的推移动态改变绘图。

但不管怎么说，有关文件：

首先，文本阅读，真是简单。

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

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

   的第一个参数是.txt文件的名称（请注意，您需要将目录设置为.txt文件所在的文件夹）。第二个参数表明您希望从文本文件中读取。然后，您可以从文件中读取数据并将其放入具有不同功能的变量中（取决于您最适合的变量）。例如，

   var=fgetl(file_text_rd);

   会把文件内容的第一行中的变量。

   var=fscanf(file_text_rd,%c);

   将把.txt文件的全部内容在变量等其他阅读功能fread和fgets。所以，根据功能的不同，您可能想要使用一些循环功能来填充您的内容var。

2. 当你与你的文件读取完成后，需要关闭该文件用：

   fclose(file_text_rd), clear file_text_rd;

接下来的部分是可能更多麻烦一点点。这是你将你阅读的字符转换为整数的部分。我为你写了一段代码，来说明实现这一点的一种方法。在这个解决方案中，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，你对如何绘制你的4D数据的一些想法，即使我真的不能赶上那部分了。

我希望我帮忙， 博扬