为什么IDL会将自己的刻度标记添加到我的自定义标记刻度标记中？

Question

我正在尝试指定自定义Y轴刻度线，但IDL不合作。

在左上角，1.0000应该是最大值，但IDL在那里放57。 57是我数据的最大数组维度。

我有一个与数组索引对应1：1的eta级别（字符串）数组，我想将它们用作刻度线。我有一些代码可以让它绘制X主刻度标记，但是IDL不断在那里抛出那个愚蠢的最大数组索引值，而不是我想要的最终刻度标记。

有没有办法可以摆脱它？

根据要求，这是代码：

;Get the total number of possible y axis values( this case has 58 )
number_of_ticks = (size( custom_levels[ min_level:max_level ] ) )[1]

;I want 6 major tick marks
number_of_major_ticks = 6

;The amount in between each tick in terms of array index
tick_step = number_of_ticks / number_of_major_ticks

;Check if we can fit another tick mark in
if ((((number_of_major_ticks - 1)+min_level) * tick_step) + tick_step) LT number_of_ticks then begin
   number_of_major_ticks = number_of_major_ticks + 1
endif

;Get the array positions of the values that will be used for tick marks
tick_array_indices = indgen( number_of_major_ticks )    
tick_array_indices = (tick_array_indices+min_level) * tick_step

;Now build the array of tick mark strings that should be displayed
y_tick_labels = strarr( number_of_major_ticks + 1 )

for i = 0, number_of_major_ticks - 1 do begin
   y_tick_labels[i] = custom_levels[ tick_array_indices[ i ] ]
endfor

;That's all the initial setup, now to actually plot the data:
if overplot EQ 1 then begin 
  CASE contour_type OF
    'Solid Line':contour, var_slice, /overplot, levels = var_levels, /FOLLOW, Color = 0, YSTYLE = 1, XSTYLE = 1, XRANGE = [0, n_points ], YRANGE = [ min_level, max_level ]
    'Dashed Line':contour, var_slice, /overplot, levels = var_levels, /FOLLOW,  C_LINESTYLE = [1], C_COLOR = 0, Color = 0, YSTYLE = 1, XSTYLE = 1, YRANGE = [ min_level, max_level ], XRANGE = [0, n_points ]  
  endcase
endif else begin
  CASE contour_type OF
    'Fill':contour, var_slice, /Fill, C_COLORS=var_colors, Background = 16777215, levels=var_levels, POSITION=[0.1, 0.25, 0.9, 0.95], /NORMAL, Color = 0, Title = 'Cross section plot between coordinates ' +  strtrim(lat[x1, y1],2) + ',' + strtrim(lon[x1, y1],2) + ' and ' + strtrim(lat[x2, y2],2) + ',' + strtrim(lon[x2, y2],2), YTICKS = number_of_major_ticks, YTICKNAME =  y_tick_labels, YTITLE = custom_levels_title, XTITLE = 'Points in between the 2 chosen coordinates', CHARSIZE = 1.2, YSTYLE = 1, XSTYLE = 1, YRANGE = [ min_level, max_level ], XRANGE = [0, n_points ]
    'Solid Line':contour, var_slice, Background = 16777215, levels=var_levels, POSITION=[0.1, 0.25, 0.9, 0.95], Color = 0, Title = 'Cross section plot between coordinates ' +  strtrim(lat[x1, y1],2) + ',' + strtrim(lon[x1, y1],2) + ' and ' + strtrim(lat[x2, y2],2) + ',' + strtrim(lon[x2, y2],2), YTICKS = number_of_major_ticks, YTICKNAME =  y_tick_labels, YTITLE = custom_levels_title, XTITLE = 'Points in between the 2 chosen coordinates', CHARSIZE = 1.2, YSTYLE = 1, XSTYLE = 1, YRANGE = [ min_level, max_level ], XRANGE = [0, n_points ]
    'Dashed Line':contour, var_slice, Background = 16777215, levels=var_levels,C_LINESTYLE = [1], C_COLOR = 0, POSITION=[0.1, 0.25, 0.9, 0.95], Color = 0, Title = 'Cross section plot between coordinates ' +  strtrim(lat[x1, y1],2) + ',' + strtrim(lon[x1, y1],2) + ' and ' + strtrim(lat[x2, y2],2) + ',' + strtrim(lon[x2, y2],2), YTICKS = number_of_major_ticks, YTICKNAME =  y_tick_labels, YTITLE = custom_levels_title, XTITLE = 'Points in between the 2 chosen coordinates', CHARSIZE = 1.2, YSTYLE = 1, XSTYLE = 1, YRANGE = [ min_level, max_level ], XRANGE = [0, n_points ]           
  endcase  
endelse    

填充案例是现在正在使用的案例。在这种情况下，var_slice是一个450x58数组。

Answer 1

伍兹，想通了。

IDL似乎要求您指定一个比您给它的标签少1个刻度线。

因此，如果您需要11个刻度线，并且您的刻度线有11个标签，请将主刻度线的数量设置为10。