坐标轴与刻度#

用途与概念#

axis 配置数据范围、映射、刻度和标签。默认主轴是 x/y；显式 range 保证不同图表使用同样数值范围。linear、log、symlog 是不同数据映射，不是页面旋转。

最小完整示例#

此文件包含画布及必要定义，可直接运行 laymesh validate 或 laymesh render，不依赖前文未声明的变量。

1# Minimal complete example: axis2page=canvas(size=(100mm,75mm),background="#ffffff")3p=plot(size=(86mm,62mm),x=axis(range=(0,4),ticks=[0,2,4],label="Time"),y=axis(range=(0,5),grid=major))4p.line(x=[0,1,2,3],y=[1,2,4,3])5page.add(p,offset=(7mm,6mm))

# Minimal complete example: axis
page=canvas(size=(100mm,75mm),background="#ffffff")
p=plot(size=(86mm,62mm),x=axis(range=(0,4),ticks=[0,2,4],label="Time"),y=axis(range=(0,5),grid=major))
p.line(x=[0,1,2,3],y=[1,2,4,3])
page.add(p,offset=(7mm,6mm))

1# Minimal complete example: axis2page=canvas(size=(100mm,75mm),background="#ffffff")3p=plot(size=(86mm,62mm),x=axis(range=(0,4),ticks=[0,2,4],label="Time"),y=axis(range=(0,5),grid=major))4p.line(x=[0,1,2,3],y=[1,2,4,3])5page.add(p,offset=(7mm,6mm))

# Minimal complete example: axis
page=canvas(size=(100mm,75mm),background="#ffffff")
p=plot(size=(86mm,62mm),x=axis(range=(0,4),ticks=[0,2,4],label="Time"),y=axis(range=(0,5),grid=major))
p.line(x=[0,1,2,3],y=[1,2,4,3])
page.add(p,offset=(7mm,6mm))

依赖文件

examples/manual/axis.lay

参数与默认行为#

裸几何长度使用画布单位，裸字号和描边宽度使用 pt。显式调用参数优先于继承和主题默认值；下面的接口参考逐项列出允许类型、可选值与默认来源。

组合用法#

ticks 配 tick_text 可显示分类文字或公式；minor_ticks 和 grid 控制细分刻度与背景网格。通过 chart.axes["x"].spine.path 选轴线，通过完整组件 bounds 对齐标题区域。

2# Independent axis gaps. Lengths are literal mm, not stretch factors.3page=canvas(size=(210 mm,128 mm),background="#ffffff")4s=plot_style(font_family="DejaVu Sans",font_size=8 pt)5p=plot(size=(195 mm,112 mm),plot_area=box(offset=(24 mm, 20 mm), size=(110 mm, 62 mm)),style=s,6 x=axis(label="Time (s)",range=(0,10),ticks=[0,1,2,8,9,10],breaks=[(2,8)],break_gap=3 mm,segment_lengths=[45 mm,62 mm],minor_ticks="auto"),7 y=axis(label="Signal (a.u.)",range=(0,100),ticks=[0,5,80,90,100],breaks=[(10,80)],break_gap=2 mm,segment_lengths=[20 mm,40 mm],line_color="#264b69"))8p.add_axis(name="temperature",side= right,offset=0 mm,9 axis=axis(label="Temperature (K)",range=(200,1000),ticks=[200,400,800,1000],breaks=[(400,800)],break_gap=4 mm,segment_lengths=[29 mm,29 mm],line_color="#a04725"))10p.add_axis(name="pressure",side= right,offset=29 mm,11 axis=axis(label="Pressure (MPa)",range=(0,100),ticks=[0,25,50,75,100],line_color="#34705a"))12a=p.line(x=[0,1,2,8,9,10],y=[1,5,9,84,92,98],marker= circle,color="#264b69",label="Signal")13b=p.line(x=[0,1,2,8,9,10],y=[220,300,380,830,910,980],y_axis="temperature",marker= diamond,color="#a04725",label="Temperature")14c=p.line(x=[0,1,2,8,9,10],y=[15,26,40,55,72,91],y_axis="pressure",line_dash=[2 mm,1 mm],color="#34705a",label="Pressure")15p.errorbar(x=[1,9],y=[5,91],yerr=[4,8],color="#264b69",cap_size=2 mm)16chart=page.add(p,offset=(6 mm,8 mm))17page.add(text(content="Independent gaps on three vertical axes",font_family="DejaVu Sans",font_size=10 pt),target=chart.plot_top_left,offset=(0 mm,-14 mm))18page.add(legend(layers=[a,b,c],columns=3,gap=3 mm,background="none"),target=chart.plot_bottom_left,offset=(0 mm,23 mm))19# This data anchor uses temperature values, including its independent break.20page.add(text(content="T",font_family="DejaVu Sans",font_size=8 pt,color="#a04725"),anchor=bottom_left,target=chart.data(x=9,y=910,y_axis="temperature"),offset=(2 mm,-2 mm))

# Independent axis gaps. Lengths are literal mm, not stretch factors.
page=canvas(size=(210 mm,128 mm),background="#ffffff")
s=plot_style(font_family="DejaVu Sans",font_size=8 pt)
p=plot(size=(195 mm,112 mm),plot_area=box(offset=(24 mm, 20 mm), size=(110 mm, 62 mm)),style=s,
 x=axis(label="Time (s)",range=(0,10),ticks=[0,1,2,8,9,10],breaks=[(2,8)],break_gap=3 mm,segment_lengths=[45 mm,62 mm],minor_ticks="auto"),
 y=axis(label="Signal (a.u.)",range=(0,100),ticks=[0,5,80,90,100],breaks=[(10,80)],break_gap=2 mm,segment_lengths=[20 mm,40 mm],line_color="#264b69"))
p.add_axis(name="temperature",side= right,offset=0 mm,
 axis=axis(label="Temperature (K)",range=(200,1000),ticks=[200,400,800,1000],breaks=[(400,800)],break_gap=4 mm,segment_lengths=[29 mm,29 mm],line_color="#a04725"))
p.add_axis(name="pressure",side= right,offset=29 mm,
 axis=axis(label="Pressure (MPa)",range=(0,100),ticks=[0,25,50,75,100],line_color="#34705a"))
a=p.line(x=[0,1,2,8,9,10],y=[1,5,9,84,92,98],marker= circle,color="#264b69",label="Signal")
b=p.line(x=[0,1,2,8,9,10],y=[220,300,380,830,910,980],y_axis="temperature",marker= diamond,color="#a04725",label="Temperature")
c=p.line(x=[0,1,2,8,9,10],y=[15,26,40,55,72,91],y_axis="pressure",line_dash=[2 mm,1 mm],color="#34705a",label="Pressure")
p.errorbar(x=[1,9],y=[5,91],yerr=[4,8],color="#264b69",cap_size=2 mm)
chart=page.add(p,offset=(6 mm,8 mm))
page.add(text(content="Independent gaps on three vertical axes",font_family="DejaVu Sans",font_size=10 pt),target=chart.plot_top_left,offset=(0 mm,-14 mm))
page.add(legend(layers=[a,b,c],columns=3,gap=3 mm,background="none"),target=chart.plot_bottom_left,offset=(0 mm,23 mm))
# This data anchor uses temperature values, including its independent break.
page.add(text(content="T",font_family="DejaVu Sans",font_size=8 pt,color="#a04725"),anchor=bottom_left,target=chart.data(x=9,y=910,y_axis="temperature"),offset=(2 mm,-2 mm))

1# BEGIN DEMO2# Independent axis gaps. Lengths are literal mm, not stretch factors.3page=canvas(size=(210 mm,128 mm),background="#ffffff")4s=plot_style(font_family="DejaVu Sans",font_size=8 pt)5p=plot(size=(195 mm,112 mm),plot_area=box(offset=(24 mm, 20 mm), size=(110 mm, 62 mm)),style=s,6 x=axis(label="Time (s)",range=(0,10),ticks=[0,1,2,8,9,10],breaks=[(2,8)],break_gap=3 mm,segment_lengths=[45 mm,62 mm],minor_ticks="auto"),7 y=axis(label="Signal (a.u.)",range=(0,100),ticks=[0,5,80,90,100],breaks=[(10,80)],break_gap=2 mm,segment_lengths=[20 mm,40 mm],line_color="#264b69"))8p.add_axis(name="temperature",side= right,offset=0 mm,9 axis=axis(label="Temperature (K)",range=(200,1000),ticks=[200,400,800,1000],breaks=[(400,800)],break_gap=4 mm,segment_lengths=[29 mm,29 mm],line_color="#a04725"))10p.add_axis(name="pressure",side= right,offset=29 mm,11 axis=axis(label="Pressure (MPa)",range=(0,100),ticks=[0,25,50,75,100],line_color="#34705a"))12a=p.line(x=[0,1,2,8,9,10],y=[1,5,9,84,92,98],marker= circle,color="#264b69",label="Signal")13b=p.line(x=[0,1,2,8,9,10],y=[220,300,380,830,910,980],y_axis="temperature",marker= diamond,color="#a04725",label="Temperature")14c=p.line(x=[0,1,2,8,9,10],y=[15,26,40,55,72,91],y_axis="pressure",line_dash=[2 mm,1 mm],color="#34705a",label="Pressure")15p.errorbar(x=[1,9],y=[5,91],yerr=[4,8],color="#264b69",cap_size=2 mm)16chart=page.add(p,offset=(6 mm,8 mm))17page.add(text(content="Independent gaps on three vertical axes",font_family="DejaVu Sans",font_size=10 pt),target=chart.plot_top_left,offset=(0 mm,-14 mm))18page.add(legend(layers=[a,b,c],columns=3,gap=3 mm,background="none"),target=chart.plot_bottom_left,offset=(0 mm,23 mm))19# This data anchor uses temperature values, including its independent break.20page.add(text(content="T",font_family="DejaVu Sans",font_size=8 pt,color="#a04725"),anchor=bottom_left,target=chart.data(x=9,y=910,y_axis="temperature"),offset=(2 mm,-2 mm))21# END DEMO

# BEGIN DEMO
# Independent axis gaps. Lengths are literal mm, not stretch factors.
page=canvas(size=(210 mm,128 mm),background="#ffffff")
s=plot_style(font_family="DejaVu Sans",font_size=8 pt)
p=plot(size=(195 mm,112 mm),plot_area=box(offset=(24 mm, 20 mm), size=(110 mm, 62 mm)),style=s,
 x=axis(label="Time (s)",range=(0,10),ticks=[0,1,2,8,9,10],breaks=[(2,8)],break_gap=3 mm,segment_lengths=[45 mm,62 mm],minor_ticks="auto"),
 y=axis(label="Signal (a.u.)",range=(0,100),ticks=[0,5,80,90,100],breaks=[(10,80)],break_gap=2 mm,segment_lengths=[20 mm,40 mm],line_color="#264b69"))
p.add_axis(name="temperature",side= right,offset=0 mm,
 axis=axis(label="Temperature (K)",range=(200,1000),ticks=[200,400,800,1000],breaks=[(400,800)],break_gap=4 mm,segment_lengths=[29 mm,29 mm],line_color="#a04725"))
p.add_axis(name="pressure",side= right,offset=29 mm,
 axis=axis(label="Pressure (MPa)",range=(0,100),ticks=[0,25,50,75,100],line_color="#34705a"))
a=p.line(x=[0,1,2,8,9,10],y=[1,5,9,84,92,98],marker= circle,color="#264b69",label="Signal")
b=p.line(x=[0,1,2,8,9,10],y=[220,300,380,830,910,980],y_axis="temperature",marker= diamond,color="#a04725",label="Temperature")
c=p.line(x=[0,1,2,8,9,10],y=[15,26,40,55,72,91],y_axis="pressure",line_dash=[2 mm,1 mm],color="#34705a",label="Pressure")
p.errorbar(x=[1,9],y=[5,91],yerr=[4,8],color="#264b69",cap_size=2 mm)
chart=page.add(p,offset=(6 mm,8 mm))
page.add(text(content="Independent gaps on three vertical axes",font_family="DejaVu Sans",font_size=10 pt),target=chart.plot_top_left,offset=(0 mm,-14 mm))
page.add(legend(layers=[a,b,c],columns=3,gap=3 mm,background="none"),target=chart.plot_bottom_left,offset=(0 mm,23 mm))
# This data anchor uses temperature values, including its independent break.
page.add(text(content="T",font_family="DejaVu Sans",font_size=8 pt,color="#a04725"),anchor=bottom_left,target=chart.data(x=9,y=910,y_axis="temperature"),offset=(2 mm,-2 mm))
# END DEMO

依赖文件

examples/plot/multi-axes-breaks.lay

常见错误与限制#

log 范围和有效数据必须为正。刻度文字与显式 ticks 长度要一致。axis.min/max 表示数值范围端点，反向轴也不改变它们的数值含义。

逐项功能说明#

axis#

配置数据范围、linear/log/symlog 映射、刻度、标签和断轴。数据范围采用原始数值，文字与线宽采用物理单位。

返回：axis

最小完整源码 · 组合源码 · 全部参数

详细行为与补充示例#

参数#

参数	用途	默认或要求
`range`	数据范围	可显式指定
`minor_ticks`	次刻度	[]；auto 显式启用
`reverse`	反向显示	false

常见用法#

x/y 是主轴名称。每个新名称须非空且唯一；side="left|right|top|bottom"，默认 right。offset=0 mm 从绘图区对应边向外量，允许负值。同侧多轴不会自动推开；根据文字宽度自行留空间。每个图层都接受 x_axis/y_axis，默认 x/y；方向不匹配或名称不存在时报错。自动范围只统计绑定该轴的数据，未使用的轴应给出显式 range。

chart.data(...) 使用原始数值，遵循所选轴的变换、反向和分段。chart.axis(name=...,anchor="start|center|end") 的 start/end 对应范围最小/最大值；reverse 不改变这个含义，center 是轴的物理中点，可能位于断口。两类锚点都随实例旋转、所在组缩放。page.add 的 offset 在页面坐标中，group.add 的 offset 在组坐标中。

轴参数	规则
`reverse=false`	翻转显示方向，不修改数据或统计结果
`scale="symlog", constant=1`	使用 `sign(x) × log(1+abs(x)/constant)`；constant 是正的原始数据单位数值，支持负数和零
`tick_text=[...]`	与显式 `ticks` 等长；字符串、`text(...)`、`formula(...)`，输入顺序保留
`tick_rotation=0 deg`	围绕刻度文字中心旋转；先测量旋转后的边界，再定位
`tick_offset=(0 mm,0 mm)`	图表局部坐标中的文字位移，x 向右、y 向下
`tick_font_size=...`, `tick_color="#..."`	刻度文字及倍率的独立样式；刻度杆也使用 tick_color，素材明确指定的文字/公式样式保留
`line_color="#..."`, `line_width=...`	该轴的线条、默认文字颜色和线宽；tick_color 可单独覆盖刻度颜色
`spine=false`	隐藏该轴轴线及断口符号，保留刻度与标签
`minor_ticks="auto"`	显式启用自动次刻度；线性/对称对数显示的数值刻度区间五等分，对数轴生成每个十进制数量级的 2–9 次刻度；原默认仍为 `[]`
`grid="none	major

标题、倍率的 label_offset/exponent_offset 继续独立生效。显示顺序、轴名和类别不是自动推断的；分类图请明确给出数值位置及 tick_text。