I'm struggling with setting a y(x) condition that varies with x range. As an example below, the code wants to plot y=x between x=0 and x=5.1; otherwise y=2x.
Upon compilation, the code spits out the following: Expression must be a scalar or 1 element array in this context:
In other words don't know how to assign an array variable 'x' into if statement.
Thank you all for your help in advance.
PRO test
x = findgen(101.0,start=0)/10.0 ; 0.0 start, 10.0 end increment of 0.1
print,x
if x lt 5.1 then begin
y = 1.0 * x ;
endif else begin
y = 2.0* x
endelse
graph1=plot(x,y,thick=2,NAME=first,/CURRENT, $
linestyle = 0, ytitle=' y',xtitle='x' ) ; O
END
The problem is the test in your IF statement. Use WHERE instead to do something like the following.
y = x ;; need to initialize variable
low = WHERE(x lt 5.1,lw,COMPLEMENT=upp,NCOMPLEMENT=up)
IF (lw[0] GT 0) THEN y[low] = x[low] ;; technically don't need this line
IF (up[0] GT 0) THEN y[upp] = 2e0*x[upp]