I am measuring a feature that is somewhat round but has lot of jagged edges. I want to use all of the areas to calculate the area. I am measuring this using hundreds of points. Anyone have any ideas ? I have searched for answers but can't seem to come up with any.
The only trick is in duplicating the first point PNT_A into PNT_A1 and creating a set of all points (A, B, C, D, A in this example). Then looping from 1 to N and accumulating the AREA, finally taking ABS() and dividing by 2.
I wrote every step as a separate command, but it can of course be much more crammed together, but will be more difficult to understand:
ASSIGN/AREA=0
I =LOOP/START,ID=NO,NUMBER=N,START=1,SKIP=,
OFFSET:XAXIS=0,YAXIS=0,ZAXIS=0,ANGLE=0
ASSIGN/AREA=AREA+(SCN1.HIT[I].X*SCN1.HIT[I+1].Y-SCN1.HIT[I].Y*SCN1.HIT[I+1].X)
LOOP/END
ASSIGN/AREA=ABS(AREA/2)
COMMENT/OPER,NO,FULL SCREEN=NO,AUTO-CONTINUE=NO,
AREA
Edit: OK, now I've done code in the '
JEFMAN spirit' too - no loops, totally undecipherable :-)) and fast!
CONSTR/SET,BASIC,PNT_A,PNT_B,PNT_C,PNT_D,PNT_A1,,
ASSIGN/N=SCN1.NUMHITS-1
ASSIGN/AR=SCN1.HIT[1..N].X*SCN1.HIT[2..N+1].Y-SCN1.HIT[1..N].Y*SCN1.HIT[2..N+1].X
ASSIGN/AR[N+1]=0
ASSIGN/AREA=ABS(SUM(AR))/2
COMMENT/OPER,NO,FULL SCREEN=NO,AUTO-CONTINUE=NO,
AREA
Coding this stuff is way above my head, but I love the math behind it, and I thought there had to be a way to calculate a triangle's area with the 3 points making its vertices as the known variables. I found something else before finding this, but the Shoelace formula is the underlying math behind it, and JEFMAN's elegant (but roundabout) solution.
Coding this stuff is way above my head, but I love the math behind it, and I thought there had to be a way to calculate a triangle's area with the 3 points making its vertices as the known variables. I found something else before finding this, but the Shoelace formula is the underlying math behind it, and JEFMAN's elegant (but roundabout) solution.
