## how to convert time unit in graphic

Asked by Kesni savitri

### Kesni savitri (view profile)

on 20 May 2013
Accepted Answer by Walter Roberson

### Walter Roberson (view profile)

i have a trouble to make my task,

i use gui matlab to show a graph.

the graph i build from the calculated differential equation use ode45 with step size 1 hour.

there is 1 until 2160 hour. and i want to show the graph time unit in 'days' without change the step size of my ode45, so how can i do?

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### Walter Roberson (view profile)

Answer by Walter Roberson

### Walter Roberson (view profile)

on 20 May 2013

For example,

```plot(t(:,1), y(:,1))
curtick = get(gca, 'xtick');
newlab = cellstr( num2str( curtick(:) ./ 24 ) );
set(gca, 'xticklabel', newlab)
```

Kesni savitri

### Kesni savitri (view profile)

on 20 May 2013

thanks for you answer, but i have 8 differensial equation, so i write...

```plot(t(:,1), y(:,1),y(:,2),y(:,3),y(:,4),y(:,5),y(:,6),y(:,7),y(:,8))
curtick = get(gca, 'xtick');
newlab = cellstr( num2str( curtick(:) ./ 24 ) );
set(gca, 'xticklabel', newlab)
```

and was error to show the graph.

```??? Error using ==> plot
Data must be a single matrix Y or a list of pairs X,Y
```
```Error in ==> ruunmodel at 5
plot(t(:,1), y(:,1),y(:,2),y(:,3),y(:,4),y(:,5),y(:,6),y(:,7),y(:,8))
```
```??? Error using ==> plot
Data must be a single matrix Y or a list of pairs X,Y
```
```Error in ==> ruunmodel at 5
plot(t(:,1), y(:,1),y(:,2),y(:,3),y(:,4),y(:,5),y(:,6),y(:,7),y(:,8))
```
Walter Roberson

### Walter Roberson (view profile)

on 20 May 2013
```plot(t(:,1), y)
```

When you specify multiple numeric vector arguments for plot() you need to use the pattern x1 y1 x2 y2 x3 y3 ... Alternately you can use a common x, and specify the y as a matrix where the columns of y form the different lines. Your y(:,1), y(:,2) etc. are already columns in the "y" matrix, so you can give it as a single argument to draw all 8 of the columns.

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