Three columns (x,y,z) in table, Loop through table for each X plot Y vs Z

table

X Y Z

A 1 3

A 2 4

A 3 10

B 1 4

B 2 4

B 4 6

C 0 1

C 1 4

C 2 5

C 3 7

C 4 8

in this scenario there will be three plots of Y vs Z. how do I structure the loop around

bar(table.Y,table.Z)

thank you.

[Frederick Awuah-Gyasi]

A separate plot for each group of A,B and C

[Star Strider]

@Frederick Awuah-Gyasi — See my Answer.

Answer 1

[Star Strider]

Try this —

CA = {'A' 1 3
    'A'  2 4 
    'A'  3 10 
    'B'  1 4 
    'B' 2 4
    'B' 4 6
    'C' 0 1
    'C' 1 4
    'C' 2 5
    'C' 3 7
    'C' 4 8};
T1 = cell2table(CA, 'VariableNames',{'X','Y','Z'})

T1 = 11×3 table
      X      Y    Z 
    _____    _    __

    {'A'}    1     3
    {'A'}    2     4
    {'A'}    3    10
    {'B'}    1     4
    {'B'}    2     4
    {'B'}    4     6
    {'C'}    0     1
    {'C'}    1     4
    {'C'}    2     5
    {'C'}    3     7
    {'C'}    4     8

[U1,~,ix] = unique(T1.X);

L = numel(U1);

figure
for k = 1:L
    subplot(L,1,k)
    v = ix == k;
    plot(T1.Y(v), T1.Z(v), '.-')
    grid
    xlabel('Y')
    ylabel('Z')
    title(U1{k})
    ylim([0 10])
end

There are ways to do this that may be more efficient for large arrays, although they require more coding as well.

.

[Frederick Awuah-Gyasi]

Thank you @Star Strider. Excatly what I was looking for. Instead of putting it all in one plot I separated it as there are 56 of them. God bless you.

[Star Strider]

As always, my pleasure!

Thank you!

[Frederick Awuah-Gyasi]

Hi @Star Strider I'm running the code now with two unique columns now. so i did this instead . the new column is B

[U1,~,ix] = unique(T(:,1:2),'rows');

but i'm getting this error

Subscripting into a table using one subscript (as in t(i)) is not supported. Specify a row subscript and a variable subscript, as in t(rows,vars). To

select variables, use t(:,i) or for one variable t.(i). To select rows, use t(i,:).

[Frederick Awuah-Gyasi]

in the meantime I will try concatenating the colums and use the old logic

[Star Strider]

I may need to know what ‘T’ is (at least some representative rows of it).

The purpose of the unique call was to get numeric indices representing the first column. Conccatenating the first colum (with the alphanumeric indicators) with a numeric column will not work. That may be throwing the error, since I get the same error when I use your unique call with the existing table.

The findgroups function will work with ‘X’ and ‘Y’ to give a unique index (although here there are no duplicates in these data).

Other parts of the code change as well —

CA = {'A' 1 3
    'A'  2 4 
    'A'  3 10 
    'B'  1 4 
    'B' 2 4
    'B' 4 6
    'C' 0 1
    'C' 1 4
    'C' 2 5
    'C' 3 7
    'C' 4 8};
T1 = cell2table(CA, 'VariableNames',{'X','Y','Z'})

T1 = 11×3 table
      X      Y    Z 
    _____    _    __

    {'A'}    1     3
    {'A'}    2     4
    {'A'}    3    10
    {'B'}    1     4
    {'B'}    2     4
    {'B'}    4     6
    {'C'}    0     1
    {'C'}    1     4
    {'C'}    2     5
    {'C'}    3     7
    {'C'}    4     8

[ix,ID] = findgroups(T1(:,1:2))

ix = 11×1

1 2 3 4 5 6 7 8 9 10

ID = 11×2 table
      X      Y
    _____    _

    {'A'}    1
    {'A'}    2
    {'A'}    3
    {'B'}    1
    {'B'}    2
    {'B'}    4
    {'C'}    0
    {'C'}    1
    {'C'}    2
    {'C'}    3
    {'C'}    4

L = numel(ix);

figure
for k = 1:L
    subplot(L,1,k)
    v = ix == k;
    plot(T1.Y(v), T1.Z(v), '.-')
    grid
    xlabel('Y')
    ylabel('Z')
%     title(U1{k})
    ylim([0 10])
end

.

[Frederick Awuah-Gyasi]

Thanks so much. So I concanated the 1st and 2nd column. This is a verison of the first code. this second version was to plot cumulations so another coulmn was added. that hurlde seems to have been crossed a last piece is to animate the plots. So for each A, B C I will have animated plots.

[U1,~,ix] = unique(T1.X);

L = numel(U1);

figure

for k = 1:L

subplot(L,1,k)

v = ix == k;

plot(T1.Y(v), T1.Z(v), '.-')

grid

xlabel('Y')

ylabel('Z')

title(U1{k})

ylim([0 10])

saveas(gcf,name)

animeVector(k) = getframe;

end

myWriter = VideoWriter('LevelMovie');

myWriter.FrameRate = 20;

open(myWriter);

writeVideo(myWriter,animeVector);

close(myWriter);

I modified the code as above but i'm getting this error :

Error using VideoWriter/writeVideo (line 414)

All 'cdata' fields in FRAMES must be the same size.

Really appecaite all the help.

[Frederick Awuah-Gyasi]

Is there a comamand or parameter to pass so that 1, and 3 even though there are not data points still take the full space. like below. Not sure how both are not consistent.

Sorry to bother you with many questions. Thanks for the help.

[Star Strider]

I have no recent experience with videoWriter, however I will do my best to see if I can get this to work.

I am eliminating the saveas call for the time being, since it may not work with the online Run feature here.

CA = {'A' 1 3
    'A'  2 4 
    'A'  3 10 
    'B'  1 4 
    'B' 2 4
    'B' 4 6
    'C' 0 1
    'C' 1 4
    'C' 2 5
    'C' 3 7
    'C' 4 8};
T1 = cell2table(CA, 'VariableNames',{'X','Y','Z'})

T1 = 11×3 table
      X      Y    Z 
    _____    _    __

    {'A'}    1     3
    {'A'}    2     4
    {'A'}    3    10
    {'B'}    1     4
    {'B'}    2     4
    {'B'}    4     6
    {'C'}    0     1
    {'C'}    1     4
    {'C'}    2     5
    {'C'}    3     7
    {'C'}    4     8

% [U1,~,ix] = unique(T1.X);
% 
% L = numel(U1);
% 
% figure
% for k = 1:L
%     subplot(L,1,k)
%     v = ix == k;
%     plot(T1.Y(v), T1.Z(v), '.-')
%     grid
%     xlabel('Y')
%     ylabel('Z')
%     title(U1{k})
%     ylim([0 10])
% end

[U1,~,ix] = unique(T1.X);
L = numel(U1);
figure
for k = 1:L
    subplot(L,1,k)
    v = ix == k;
    plot(T1.Y(v), T1.Z(v), '.-')
    grid
    xlabel('Y')
    ylabel('Z')
    title(U1{k})
    ylim([0 10])
%     saveas(gcf,name)
    GF = getframe(gcf)                          % Test
    animeVector(k) = getframe(gcf);
end

GF = struct with fields:
       cdata: [433×577×3 uint8]
    colormap: []

GF = struct with fields:
       cdata: [433×577×3 uint8]
    colormap: []

GF = struct with fields:
       cdata: [433×577×3 uint8]
    colormap: []

 
myWriter = VideoWriter('LevelMovie');
myWriter.FrameRate = 20;
open(myWriter);
writeVideo(myWriter,animeVector);
close(myWriter);

Using:

animeVector(k) = getframe(gcf);

appears to run without error.

.

[Star Strider]

My apologies, however at this point I am completely lost.

I have no idea what you want to do.

[Frederick Awuah-Gyasi]

@Star Strider I have edited the commnent above. In response to your comment . Hope it makes sense now. sorry about the confusion.

[Star Strider]

I am still not certain what you want to do with it.

[Frederick Awuah-Gyasi]

@Star Strider

If my data is of this format with the added W column. How do I get the animation for A, B C. sepearately.

X W Y Z

A 1 0 3

A 1 2 3

A 1 3 3

A 2 0 5

A 2 2 7

A 2 3 8

B 1 0 3

B 1 1 3

B 1 3 3

B 2 0 12

B 2 2 1

B 2 3 3

C 1 0 2

C 1 1 1

C 1 2 3

C 2 0 4

C 2 1 3

C 2 2 6

I have edited the code to this to this :

[ix,ID] = findgroups(T1(:,1:2))

L = numel(U1);

figure

for k = 1:L

figure(k) %subplot(L,1,k)

v = ix == k;

plot(T1.Y(v), T1.Z(v), '.-')

grid

xlabel('Y')

ylabel('Z')

title(U1{k})

ylim([0 10])

GF = getframe(gcf) % Test

animeVector(k) = getframe(gcf);

end

myWriter = VideoWriter('LevelMovie');

myWriter.FrameRate = 20;

open(myWriter);

writeVideo(myWriter,animeVector);

close(myWriter);

Does it look right.

[Star Strider]

I have no idea if it looks right, however with a few changes in the code, it runs without error —

CA = {'A'    1    0        3 
      'A'    1    2        3 
      'A'    1    3        3 
      'A'    2    0        5
      'A'    2    2        7 
      'A'    2    3        8
      'B'    1    0        3 
      'B'    1    1        3 
      'B'    1    3        3 
      'B'    2    0       12
      'B'    2    2        1
      'B'    2    3        3
      'C'    1    0        2 
      'C'    1    1        1 
      'C'    1    2        3 
      'C'    2    0        4
      'C'    2    1        3
      'C'    2    2        6};

T1 = cell2table(CA,'VariableNames',{'X','W','Y','Z'})

T1 = 18×4 table
      X      W    Y    Z 
    _____    _    _    __

    {'A'}    1    0     3
    {'A'}    1    2     3
    {'A'}    1    3     3
    {'A'}    2    0     5
    {'A'}    2    2     7
    {'A'}    2    3     8
    {'B'}    1    0     3
    {'B'}    1    1     3
    {'B'}    1    3     3
    {'B'}    2    0    12
    {'B'}    2    2     1
    {'B'}    2    3     3
    {'C'}    1    0     2
    {'C'}    1    1     1
    {'C'}    1    2     3
    {'C'}    2    0     4

[ix,ID] = findgroups(T1(:,1:2))

ix = 18×1

1 1 1 2 2 2 3 3 3 4

ID = 6×2 table
      X      W
    _____    _

    {'A'}    1
    {'A'}    2
    {'B'}    1
    {'B'}    2
    {'C'}    1
    {'C'}    2

L = size(ID,1);
figure
for k = 1:L
    figure(k) %subplot(L,1,k)    
    v = ix == k;
    plot(T1.Y(v), T1.Z(v), '.-')
    grid
    xlabel('Y')
    ylabel('Z')
    title(sprintf('%s %d',ID{k,1}{:},ID{k,2}))
    ylim([0 10])
    GF = getframe(gcf)                          % Test
    animeVector(k) = getframe(gcf);
end

GF = struct with fields:
       cdata: [433×577×3 uint8]
    colormap: []

GF = struct with fields:
       cdata: [433×577×3 uint8]
    colormap: []

GF = struct with fields:
       cdata: [433×577×3 uint8]
    colormap: []

GF = struct with fields:
       cdata: [433×577×3 uint8]
    colormap: []

GF = struct with fields:
       cdata: [433×577×3 uint8]
    colormap: []

GF = struct with fields:
       cdata: [433×577×3 uint8]
    colormap: []

myWriter = VideoWriter('LevelMovie');
myWriter.FrameRate = 20;
open(myWriter);
writeVideo(myWriter,animeVector);
close(myWriter);

I have no idea how this relates to your other post Cross product of two tables without common key so I will leave that alone.

.

[Frederick Awuah-Gyasi]

Thanks @Star Strider. Instead of A1 A2 B1 B2 C1 C2 for the animations. Will it be possible to have A, B C. So the animation shows A {A1 and A2 ) combined, B(B1 and B2) C (C1 and C2) . W is accually a day column shown ie. day 1 2 3 etc.

yeah that post is related but didnt want to confused the two. will explain that later. Z column must have data (0,1,2,3,4) there are instances where the are no data points so will have to fix that.

really appreciate all the help.

[Star Strider]

I have no idea how you want to combine them.

Try this —

CA = {'A'    1    0        3 
      'A'    1    2        3 
      'A'    1    3        3 
      'A'    2    0        5
      'A'    2    2        7 
      'A'    2    3        8
      'B'    1    0        3 
      'B'    1    1        3 
      'B'    1    3        3 
      'B'    2    0       12
      'B'    2    2        1
      'B'    2    3        3
      'C'    1    0        2 
      'C'    1    1        1 
      'C'    1    2        3 
      'C'    2    0        4
      'C'    2    1        3
      'C'    2    2        6};

T1 = cell2table(CA,'VariableNames',{'X','W','Y','Z'})

T1 = 18×4 table
      X      W    Y    Z 
    _____    _    _    __

    {'A'}    1    0     3
    {'A'}    1    2     3
    {'A'}    1    3     3
    {'A'}    2    0     5
    {'A'}    2    2     7
    {'A'}    2    3     8
    {'B'}    1    0     3
    {'B'}    1    1     3
    {'B'}    1    3     3
    {'B'}    2    0    12
    {'B'}    2    2     1
    {'B'}    2    3     3
    {'C'}    1    0     2
    {'C'}    1    1     1
    {'C'}    1    2     3
    {'C'}    2    0     4

[ix,ID] = findgroups(T1(:,1:2))

ix = 18×1

1 1 1 2 2 2 3 3 3 4

ID = 6×2 table
      X      W
    _____    _

    {'A'}    1
    {'A'}    2
    {'B'}    1
    {'B'}    2
    {'C'}    1
    {'C'}    2

L = size(ID,1);
figure
for k = 1:2:L
    figure(k) %subplot(L,1,k)    
    v = find(ix == k);
    v2 = v:v+5;
    plot(T1.Y(v2(1:3)), T1.Z(v2(1:3)), '.-')
    hold on
    plot(T1.Y(v2(1:3)+3), T1.Z(v2(1:3)+3), '.-')
    hold off
    grid
    xlabel('Y')
    ylabel('Z')
    title(sprintf('%s',ID{k,1}{:}))
    ylim([0 10])
    GF = getframe(gcf)                          % Test
    animeVector(k) = getframe(gcf);
end

v = 3×1

1 2 3

GF = struct with fields:
       cdata: [433×577×3 uint8]
    colormap: []

v = 3×1

7 8 9

GF = struct with fields:
       cdata: [433×577×3 uint8]
    colormap: []

v = 3×1

13 14 15

GF = struct with fields:
       cdata: [433×577×3 uint8]
    colormap: []

myWriter = VideoWriter('LevelMovie');
myWriter.FrameRate = 20;
open(myWriter);
writeVideo(myWriter,animeVector);

Error using VideoWriter/writeVideo
The 'cdata' field of FRAME must not be empty

close(myWriter);

This combines the plots.

I defer to you to solve the writeVideo error.

.

[Frederick Awuah-Gyasi]

Thank you so much @Star Strider. Great help.

[Frederick Awuah-Gyasi]

@Star Strider: what I want to be able to do is loop through and have A1 and A2 producing one animation,B1,B2 producing a second animation and C1 C2 producing a 3rd animation.

this code

for k = 1:L

figure(k) %subplot(L,1,k)

v = find(ix == k);

plot(T1.Y(v), T1.Z(v), '.-')

grid

xlabel('Y')

ylabel('Z')

title(sprintf('%s %d',ID{k,1}{:},ID{k,2}))

ylim([0 10])

%GF = getframe(gcf) % Test

%Vector(k) = getframe(gcf);

end

produces A1, A2, B1, B2, C1, C2. I think my use of the word combine was wrong. wanted A1, A2 producing an animation separeate from B1, B2. Hope this makes sense. Sorry for bothering you so long.

[Star Strider]

That is what my earlier code did.

Please experiment with the code I already wrote to get the result you want.

I am lost and obviously cannot figure this out.

[Frederick Awuah-Gyasi]

@Star Strider so sorry I lost you. I'm back to the earlier code and will keep you posted tonight. I really do appreciate all the help.

[Star Strider]

As always, my pleasure!

I just do not know where else to go with this, since we seem to be in an infinite loop.

[Frederick Awuah-Gyasi]

@Star Strider this code produces 3 .mp4 files which I want. but Level_1_Movie_A.mp4 for instanfce should be just for A(show only A1 and A2) same for B and C. somehow the if condition is not working. Any ideas?

CA = {'A' 1 0 3

'A' 1 2 3

'A' 1 3 3

'A' 2 0 5

'A' 2 2 7

'A' 2 3 8

'B' 1 0 3

'B' 1 1 3

'B' 1 3 3

'B' 2 0 12

'B' 2 2 1

'B' 2 3 3

'C' 1 0 2

'C' 1 1 1

'C' 1 2 3

'C' 2 0 4

'C' 2 1 3

'C' 2 2 6};

T1 = cell2table(CA,'VariableNames',{'X','W','Y','Z'});

[ix,ID] = findgroups(T1(:,1:2));

[U1,~,ixx] = unique(T1.X);

L = size(ID,1);

Names = unique(T1.X)

M = numel(U1);

for b = 1:length(Names)

for k = 1:L

figure(k) %subplot(L,1,k)

%

v = find(ix == k);

data=unique(T1.X(v))

Names(b)

ismember( Names(b), data )

if ismember( Names(b), data )

T1.X(v)

plot(T1.Y(v), T1.Z(v), '.-')

grid

xlabel('Y')

ylabel('Z')

title(sprintf('%s %d',ID{k,1}{:},ID{k,2}))

ylim([0 10])

GF = getframe(gcf) % Test

Vector(k) = getframe(gcf);

end

end

moviename = strcat('Level_1_Movie_', Names(b))

myWriter = VideoWriter(moviename{1},'MPEG-4');

myWriter.FrameRate = 20;

open(myWriter);

writeVideo(myWriter,Vector);

close(myWriter);

end

[Star Strider]

No ideas.

I have given up any hope of understanding this.

[Frederick Awuah-Gyasi]

Thanks @Star Strider. I will try posting it as a question. Let's see if anyone comes to help. I will keep trying too. Now I'm getting the 3 animations except each animation should be exclusive to a group from column X

[Star Strider]

As always, my pleasure!

Perhaps someone else has some new insights that I do have not at this point.

Answer 2

[KSSV]

Let data be your three column matrix.

x = data(:,1) ;
y = data(:,2) ;
z = data(:,3) ; 


xi = unique(x) ;
yi = unique(y) ;

nx = length(xi) ; 
ny = length(yi) ;

% Matrices
[X,Y] = meshgrid(x,y) ; 
Z = reshape(z,[ny,nx]) ;

[Frederick Awuah-Gyasi]

Thank you. I will try this out. But was hoping for example

For X in list (X) :

plot(Y,Z)

For if X = A

the data to plot will beb

Y Z

1 3

2 4

3 10