Odtnhj

I draw graphs using metapost in LuaLatex. It is more convienient than first use metapost to create graphs and then insert the graphs. But I don't know how to put two graphs in the same row. For example, how to put the following two graphs in the same row? Thank you very much.

RequirePackageluatex85
documentclass[12pt]amsart
usepackagefloat
usepackageluamplib

begindocument


beginfigure[H]
beginmplibcode
beginfig(1)
pair A,L,R,N;
A[1] := (0,2cm);

for i=2 upto 5:
A[i] := A[i-1] rotated -360/5;
endfor;

draw A[1]--A[2];
draw A[2]--A[3];
draw A[3]--A[4];
draw A[4]--A[5];
draw A[5]--A[1];
draw A[1]--A[4];

endfig;
endmplibcode
endfigure


beginfigure[H]
beginmplibcode
beginfig(1)
pair A,L,R,N,t;
path p;

A[1] := (0,2cm);

for i=2 upto 5:
A[i] := A[i-1] rotated -360/5;
endfor;

draw A[1]..A[2]..A[3]..A[4]..A[5]..A[1];

endfig;
endmplibcode
endfigure

enddocument

In you document you use two figures. LaTeX never places multiple figures in the same row, so you have to place both mplibcode environments in the same figure environment. (You can also combine them into one mplibcode environment with multiple beginfig(...) endfig; groups, but using different mplibcode environemnts makes it easier to separate the drawings.

Then there is a remaining problem:
After beginfigure, TeX is in vertical mode.
If you add multiple hboxes (through mplibcode) while vertical mode is active, TeX stacks them vertically.
So you want to enter horizontal mode first: Add leavevmode before the first mplibcode environment:

RequirePackageluatex85
documentclass[12pt]amsart
usepackagefloat
usepackageluamplib

begindocument


beginfigure[H]
 leavevmode
beginmplibcode
beginfig(1)
pair A,L,R,N;
A[1] := (0,2cm);

for i=2 upto 5:
A[i] := A[i-1] rotated -360/5;
endfor;

draw A[1]--A[2];
draw A[2]--A[3];
draw A[3]--A[4];
draw A[4]--A[5];
draw A[5]--A[1];
draw A[1]--A[4];

endfig;
endmplibcode% <- Omit this comment to add a space between the graphs.
beginmplibcode
beginfig(1)
pair A,L,R,N,t;
path p;

A[1] := (0,2cm);

for i=2 upto 5:
A[i] := A[i-1] rotated -360/5;
endfor;

draw A[1]..A[2]..A[3]..A[4]..A[5]..A[1];

endfig;
endmplibcode
endfigure

enddocument