plotframe - plot a frame with scaling and grids

### Calling Sequence

  `plotframe(rect,tics,[arg_opt1,arg_opt2,arg_opt3])`

### Parameters

- `rect` : vector `[xmin,ymin,xmax,ymax]`.
- `tics` : vector `[nx,mx,ny,my]` where `mx, nx` (resp. `my, ny`) are the number of x-axis (resp. y-axis) intervals and subintervals.
- `arg_optX` : optional arguments up to three and choosen among.

- `flags` : vector `[wantgrids,findbounds]` where `wantgrids` is a boolean variable (`%t` or `%f`) which indicates gridding. `findbounds` is a boolean variable. If `findbounds` is `%t`, the bounds given in `rect` are allowed to be slightly modified (in fact always increased) in order to have simpler graduations: then `tics(2)` and `tics(4)` are ignored.
- `captions` : vector of 3 strings `[title,x-leg,y-leg]` corresponding respectively to the title of the plot and the captions on the x-axis and the y-axis.
- `subwin` : a vector of size 4 defining the sub window. The sub window is specified with the parameter `subwin=[x,y,w,h]` (upper-left, width, height). The values in `subwin` are specified using proportion of the width or height of the current graphics window (see `xsetech`).

### Description

`plotframe` is used with 2D plotting functions `plot2d`, `plot2d1`,... to set a graphics frame. It must be used before `plot2d` which should be invoked with the "000" superposition mode.

### Examples

    x=[-0.3:0.8:27.3]';
    y=rand(x);
    rect=[min(x),min(y),max(x),max(y)];
    tics=[4,10,2,5];    //4 x-intervals and 2 y-intervals
    plotframe(rect,tics,[%f,%f],["My plot","x","y"],[0,0,0.5,0.5])
    plot2d(x,y,2,"000")
    plotframe(rect,tics,[%t,%f],["My plot with grids","x","y"],[0.5,0,0.5,0.5])
    plot2d(x,y,3,"000")
    plotframe(rect,tics,[%t,%t],..
    ["My plot with grids and automatic bounds","x","y"],[0,0.5,0.5,0.5])
    plot2d(x,y,4,"000")
    plotframe(rect,tics,[%f,%t],..
     ["My plot without grids but with automatic bounds","x","y"],..
     [0.5,0.5,0.5,0.5])
    plot2d(x,y,5,"000")
    xset("default")

### See Also

`plot2d` `graduate` `xsetech`