Hans, This sample code will give you an idea of my last feature request for mp-tool. Often, I will design my schematic on graph paper, then start to code. But there are times when I like to work interactively, write a little code, test to see what I get, adjust, ... When I am in that mode, a grid is "very" helpful. Once I am through with adjustments, I simply comment out the line " drawgrid(0,0,20,10,1u,1u);". My drawgrid routine was stolen from the schema.mp file and adjusted for a quick fix (I am writing for a deadline again), but it works. But it would be nice if something like this were in mp-tool. Turn on your numbered grid, work interactively, turn it off when done. Very nice. Happy New Year! input mp-tool def drawgrid(expr xo,yo,nx,ny,sx,sy)= begingroup save cpen,result; pen cpen; picture result; cpen:=pencircle scaled 1pt; result:=nullpicture; for x=0 upto nx: for y=0 upto ny: addto result doublepath (x*sx,y*sy) withpen cpen; endfor endfor defaultfont:="cmr7"; defaultscale:=7pt/fontsize defaultfont; for x=0 upto nx: addto result also thelabel.bot(decimal(x),(x*sx,0)) withpen cpen; endfor for y=0 upto ny: addto result also thelabel.lft(decimal(y),(0,y*sy)) withpen cpen; endfor; draw result; endgroup enddef; beginfig(6); %initialize scale numeric u; 1u=0.25in; drawgrid(0,0,20,10,1u,1u); %draw line for measurement later draw (0,0)--(10u,0); %draw base for pivot path base; base:=unitsquare xyscaled (4u,1u); base:=base shifted (8u,-2u); stripe_path_a(withcolor black)(draw) base withcolor white; draw (8u,-1u)--(12u,-1u); %draw pivot path tri; tri:=(-1,-1)--(0,1)--(1,-1)--cycle; tri:=tri scaled u; tri:=tri shifted (10u,0); fill tri withcolor 0.85white; %initialize pendulum path pend; pend:=(9.5,-0.5)--(10.5,-0.5)--(10.5,10.5)--(9.5,10.5)--cycle; pend:=pend scaled u; draw pend; %draw pivot point drawdot(10u,0) withpen pencircle scaled 6pt; %draw spring block left path left; left:=(2,9)--(3,9)--(3,11)--(2,11)--cycle; left:=left scaled u; stripe_path_a(withcolor black)(draw) left withcolor white; draw (3u,9u)--(3u,11u); %draw spring block right path right; right:=(17,9)--(18,9)--(18,11)--(17,11)--cycle; right:=right scaled u; stripe_path_a(withcolor black)(draw) right withcolor white; draw (17u,9u)--(17u,11u); %spring path spring, link; link:=(0,0)--(0.25,0.5)--(0.75,-0.5)--(1,0); spring:=link; for k=1 upto 2: spring:=spring--(link shifted (k,0)); endfor spring:=spring scaled u; %left spring draw (3u,10u)--(5u,10u); draw spring shifted (5u,10u); draw (8u,10u)--(10u,10u); %right spring draw (10u,10u)--(12u,10u); draw spring shifted (12u,10u); draw (15u,10u)--(17u,10u); %draw spring contact point drawdot(10u,10u) withpen pencircle scaled 6pt; %label springs label(btex $k$ etex, (6.5u,11u)); label(btex $k$ etex, (13.5u,11u)); %label some measurement lengths pair A, B, C, D, E; A:=(1u,0); B:=(1u,10u); C:=(5u,0); D:=(5u,5u); E:=(10u,5u); drawdblarrow A--B; label.lft(btex $L$ etex, 0.5[A,B]); drawdblarrow C--D; draw (0,10u)--(2u,10u); label.lft(btex $L/2$ etex, 0.5[C,D]); draw (4u,5u)--(6u,5u); drawdot(E) withpen pencircle scaled 6pt; label.top(btex cm etex,E shifted (0,5)); endfig;