# Auto scale left axis based on currently displayed waves

Function AutoscaleLeft()
if((stringmatch(AxisList(""),"*bottom*")==0)||(stringmatch(AxisList(""),"*left*")==0))
print "no left or bottom axis"
else
getaxis/q bottom
variable num=0,minB=V_min,maxB=V_max,minL=inf,maxL=-inf
do
if (waveexists(WaveRefIndexed("",num,1)))
Duplicate/o WaveRefIndexed("",num,1), temp
if(wavemax(temp,minB,maxB)>maxL)
maxL=wavemax(temp,minB,maxB)
endif
if(wavemin(temp,minB,maxB)<minL)
minL=wavemin(temp,minB,maxB)
endif
else
break
endif
num+=1
while(1)
setaxis left, minL,maxL
killwaves/z temp
endif
End
"Autoscale Left Axis",/q ,AutoscaleLeft()
End
"Autoscale Left Axis",/q ,AutoscaleLeft()
End
I see you're autoscaling the Y axis to the Y data visible in the graph's current X range.

You're code is essentially re-implementing:

SetAxis/A=2 left

except that your code "locks" the left axis range to the current Y min/max over the current X range and assumes that all the traces are waveforms (you're using x scaling to select "visible" Y values).

That said, this implementation is a bit faster:
Function SimpleAutoscaleLeft()
if((stringmatch(AxisList(""),"*bottom*")==0)||(stringmatch(AxisList(""),"*left*")==0))
print "no left or bottom axis"
else
Variable timerRefNum=StartMSTimer
getaxis/q bottom
variable num=0,minB=V_min,maxB=V_max,minL=inf,maxL=-inf
do
WAVE/Z w= WaveRefIndexed("",num,1)
if (waveexists(w))
WaveStats/Q/M=0/R=(minB,maxB) w // /M=0 is fast, and we do it only once, not 4 calls to wavemax/min
maxL=max(maxL, V_max)
minL=min(minL,V_min)
else
break
endif
num+=1
while(1)
Variable microSeconds = stopMSTimer(timerRefNum)
Print microSeconds/10000, "Simple: microseconds per iteration"
setaxis left, minL,maxL
endif
End

--Jim Prouty
Software Engineer, WaveMetrics, Inc.

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