Have a look at the following code:
x = findgen(128)
y = 1.0 + 0.1*randomn(seed,128)
y2 = 1.0 + 0.2 randomn(seed,128)
b = widget_base( xsize=480, xoffset=940, ysize=360, yoffset=0 )
w = widget_window( b, x_scroll_size=470, y_scroll_size=350 )
widget_control, b, /realize
widget_control, w, get_value=d
p = plot( x, y, current=d, xstyle=2, ystyle=2 )
p2 = plot( x, y2, color='red', linestyle='', symbol='+', current=d, /overplot )
d.uvalue = { x:x, y:y, y2:y2, b:b, p:p, p2:p2 }
end
This creates a widget window, w, under a base, b, and then places
two overlapping plots within that window. Now, if the data changes for the second plot, I would like to do the following steps:
y3 = 1.0 + 0.2 randomn(seed,128) ; new data
p2.delete ; erases the p2 data in the plot p2 = plot( x, y3, color='red, , linestyle='', symbol='+', current=d, /overplot )
d.uvalue.p2 = p2 ; store the plot identifier in the window's uvalue structure
The last line generates the following error message:
% Attempt to store into an expression: Structure reference.
% Execution halted at: $MAIN$
What has happened is that IDL forgot the type of d.uvalue.p2, so
when I try to put a new (identical) p2 there, it rejects the attempt.
This turns out to be a huge hassle for me.
My solution is a kludge, which is to create a new structure for
d.uvalue and replace the whole thing, rather than just one element.
Is there a better, simpler way?
On 12/12/2017 02:44 AM, Jonathan wrote:
Have a look at the following code:
x = findgen(128)
y = 1.0 + 0.1*randomn(seed,128)
y2 = 1.0 + 0.2 randomn(seed,128)
b = widget_base( xsize=480, xoffset=940, ysize=360, yoffset=0 )
w = widget_window( b, x_scroll_size=470, y_scroll_size=350 ) widget_control, b, /realize
widget_control, w, get_value=d
p = plot( x, y, current=d, xstyle=2, ystyle=2 )
p2 = plot( x, y2, color='red', linestyle='', symbol='+', current=d, /overplot )
d.uvalue = { x:x, y:y, y2:y2, b:b, p:p, p2:p2 }
end
This creates a widget window, w, under a base, b, and then places
two overlapping plots within that window. Now, if the data changes for the second plot, I would like to do the following steps:
y3 = 1.0 + 0.2 randomn(seed,128) ; new data
p2.delete ; erases the p2 data in the plot p2 = plot( x, y3, color='red, , linestyle='', symbol='+', current=d, /overplot )
d.uvalue.p2 = p2 ; store the plot identifier in the window's uvalue structure
The last line generates the following error message:
% Attempt to store into an expression: Structure reference.
% Execution halted at: $MAIN$
What has happened is that IDL forgot the type of d.uvalue.p2, so
when I try to put a new (identical) p2 there, it rejects the attempt.
This turns out to be a huge hassle for me.
My solution is a kludge, which is to create a new structure for
d.uvalue and replace the whole thing, rather than just one element.
Is there a better, simpler way?
; a simpler way:
p2.putData, y3
; ps: a '*' is missing in the definition of y2 & y3
y2 = 1.0 + 0.2 * randomn(seed,128)
y3 = 1.0 + 0.2 * randomn(seed,128)
; |
Directly updating the values is also much faster than creating a new
plot. I hope this help,
Markus
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