Cfrgtkky

I'm using following asymptote code.

size(6cm,4cm,false);

import graph;



real f(real x) {return sqrt(x);}

real xmin=0, xmax=50, xStep = 5, xstep = 0;

real ymin=0, ymax=7, yStep = 1, ystep = 0;



draw(graph(f,xmin,xmax,n=200),1bp+blue);



xlimits(xmin,xmax,crop=true); 

ylimits(ymin,ymax,crop=true); 



xaxis(BottomTop,nullpen,Ticks("%",extend=true,Step=xStep,step=xstep,pTick=mediumgrey,ptick=lightgrey));

yaxis(LeftRight,nullpen,Ticks("%",extend=true,Step=yStep,step=ystep,pTick=mediumgrey,ptick=lightgrey));



ticks Tx = Ticks(Label(fontsize(5pt)),Step=xStep,step=xstep,pTick=black,ptick=black,NoZero,Size=2,size=1);

xaxis(Tx,Arrow(size=3),above=true);



ticks Ty = Ticks(shift(0,1)*Label(fontsize(5pt)),Step=yStep,step=ystep,pTick=black,ptick=black,NoZero,Size=2,size=1);

yaxis(Ty,Arrow(size=3),above=true);



shipout(bbox(xmargin=1mm,red+1bp));

I need to had something (a small sticker with number inside) on top of the upper left corner of the picture. I tested several ways without success.

Here is one way. I modified your code to add a boxed label after the bounding box is drawn but before shipout.

I located the box and label by trial and error. For example, I don't know why the "ySticker" variable must be so large.

size(6cm,4cm,false);

import graph;



real f(real x) {return sqrt(x);}

real xmin=0, xmax=50, xStep = 5, xstep = 0;

real ymin=0, ymax=7, yStep = 1, ystep = 0;



draw(graph(f,xmin,xmax,n=200),1bp+blue);



xlimits(xmin,xmax,crop=true); 

ylimits(ymin,ymax,crop=true); 



xaxis(BottomTop,nullpen,Ticks("%",extend=true,Step=xStep,step=xstep,pTick=mediumgrey,ptick=lightgrey));

yaxis(LeftRight,nullpen,Ticks("%",extend=true,Step=yStep,step=ystep,pTick=mediumgrey,ptick=lightgrey));



ticks Tx = Ticks(Label(fontsize(5pt)),Step=xStep,step=xstep,pTick=black,ptick=black,NoZero,Size=2,size=1);

xaxis(Tx,Arrow(size=3),above=true);



ticks Ty = Ticks(shift(0,1)*Label(fontsize(5pt)),Step=yStep,step=ystep,pTick=black,ptick=black,NoZero,Size=2,size=1);

yaxis(Ty,Arrow(size=3),above=true);



frame f = bbox(xmargin=1mm,red+1bp,Draw);



real xSticker = 0.0;

real ySticker = 110.0;

filldraw(f, shift(xSticker,ySticker)*scale(15.0,8.0)*shift(-0.5,-0.5)*unitsquare, white, black);

label(f, scale(0.5)*"test", (xSticker,ySticker));



shipout(f);