示例：带奇异值的等值线图

绘图 > 等值线图 > 示例：带奇异值的等值线图

示例：带奇异值的等值线图

1. 使用已知奇点定义 2 变量函数。

单击复制此表达式

2. 在等值线图中F。

单击复制此表达式

<region id="ID0EIL5QB" actualWidth="263.52" actualHeight="245.20000000000002" top="57.600000000000009" left="19.200000000000003" xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/worksheet50">
  <plot background-type="transparent" xml:lang="zh_CN">
    <contourPlot xml:lang="zh_CN">
      <axes xml:lang="zh_CN">
        <xAxis rank="1" legend-position="PlotBoundaryBottom" start="-10" end="10" xml:lang="zh_CN">
          <axisLine position="ticknumberlock" positionticmark="0" legendWidth="0" xml:lang="zh_CN" />
          <axisGrid xml:lang="zh_CN">
            <gridFrequency xml:lang="zh_CN">11</gridFrequency>
            <gridLabels display="true" xml:lang="zh_CN" />
            <gridLines xml:lang="zh_CN" />
            <tickMarks display="true" xml:lang="zh_CN" />
          </axisGrid>
          <axisLabel xml:lang="zh_CN" />
          <markers xml:lang="zh_CN" />
          <numberFormat xml:lang="zh_CN">
            <general precision="3" show-trailing-zeros="false" radix="dec" zero-threshold="15" imaginary-value="i" exponential-threshold="3" xml:lang="zh_CN" />
          </numberFormat>
          <xyDomain scale-type="linear" auto-scale="true" xml:lang="zh_CN">
            <startValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </startValue>
            <endValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </endValue>
          </xyDomain>
        </xAxis>
        <yAxis rank="1" legend-position="PlotBoundaryLeft" start="-10" end="10" xml:lang="zh_CN">
          <axisLine position="ticknumberlock" positionticmark="0" legendWidth="0" xml:lang="zh_CN" />
          <axisGrid xml:lang="zh_CN">
            <gridFrequency xml:lang="zh_CN">11</gridFrequency>
            <gridLabels display="true" xml:lang="zh_CN" />
            <gridLines xml:lang="zh_CN" />
            <tickMarks display="true" xml:lang="zh_CN" />
          </axisGrid>
          <axisLabel xml:lang="zh_CN" />
          <markers xml:lang="zh_CN" />
          <numberFormat xml:lang="zh_CN">
            <general precision="3" show-trailing-zeros="false" radix="dec" zero-threshold="15" imaginary-value="i" exponential-threshold="3" xml:lang="zh_CN" />
          </numberFormat>
          <xyDomain scale-type="linear" auto-scale="true" xml:lang="zh_CN">
            <startValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </startValue>
            <endValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </endValue>
          </xyDomain>
        </yAxis>
        <zAxis rank="1" start="-32" end="32" xml:lang="zh_CN">
          <axisLine position="origin" positionticmark="5" legendWidth="0" xml:lang="zh_CN" />
          <axisGrid xml:lang="zh_CN">
            <gridFrequency xml:lang="zh_CN">9</gridFrequency>
            <gridLabels display="true" xml:lang="zh_CN" />
            <gridLines xml:lang="zh_CN" />
            <tickMarks display="true" xml:lang="zh_CN" />
          </axisGrid>
          <axisLabel xml:lang="zh_CN" />
          <markers xml:lang="zh_CN" />
          <numberFormat xml:lang="zh_CN">
            <general precision="3" show-trailing-zeros="false" radix="dec" zero-threshold="15" imaginary-value="i" exponential-threshold="3" xml:lang="zh_CN" />
          </numberFormat>
          <zDomain scale-type="linear" auto-scale="true" xml:lang="zh_CN">
            <startValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </startValue>
            <endValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </endValue>
          </zDomain>
        </zAxis>
      </axes>
      <contour color="#FF000000" show-lables="false" resultRef="20" xml:lang="zh_CN" />
      <graph-size width="192" height="192" xml:lang="zh_CN" />
      <plotEquation xml:lang="zh_CN">
        <math xml:lang="zh_CN">
          <id labels="VARIABLE" xml:space="preserve" xml:lang="zh_CN" label-is-contextual="true" xmlns="http://schemas.mathsoft.com/math50">F</id>
        </math>
        <math xml:lang="zh_CN">
          <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
        </math>
      </plotEquation>
    </contourPlot>
  </plot>
</region>

3. 将 Z 轴的范围设在 -25 到 25 之间。

单击复制此表达式

<region id="ID0E4M5QB" actualWidth="263.52" actualHeight="245.20000000000002" top="326.40000000000003" left="19.200000000000003" xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/worksheet50">
  <plot background-type="transparent" xml:lang="zh_CN">
    <contourPlot xml:lang="zh_CN">
      <axes xml:lang="zh_CN">
        <xAxis rank="1" legend-position="PlotBoundaryBottom" start="-10" end="10" xml:lang="zh_CN">
          <axisLine position="ticknumberlock" positionticmark="0" legendWidth="0" xml:lang="zh_CN" />
          <axisGrid xml:lang="zh_CN">
            <gridFrequency xml:lang="zh_CN">11</gridFrequency>
            <gridLabels display="true" xml:lang="zh_CN" />
            <gridLines xml:lang="zh_CN" />
            <tickMarks display="true" xml:lang="zh_CN" />
          </axisGrid>
          <axisLabel xml:lang="zh_CN" />
          <markers xml:lang="zh_CN" />
          <numberFormat xml:lang="zh_CN">
            <general precision="3" show-trailing-zeros="false" radix="dec" zero-threshold="15" imaginary-value="i" exponential-threshold="3" xml:lang="zh_CN" />
          </numberFormat>
          <xyDomain scale-type="linear" auto-scale="true" xml:lang="zh_CN">
            <startValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </startValue>
            <endValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </endValue>
          </xyDomain>
        </xAxis>
        <yAxis rank="1" legend-position="PlotBoundaryLeft" start="-10" end="10" xml:lang="zh_CN">
          <axisLine position="ticknumberlock" positionticmark="0" legendWidth="0" xml:lang="zh_CN" />
          <axisGrid xml:lang="zh_CN">
            <gridFrequency xml:lang="zh_CN">11</gridFrequency>
            <gridLabels display="true" xml:lang="zh_CN" />
            <gridLines xml:lang="zh_CN" />
            <tickMarks display="true" xml:lang="zh_CN" />
          </axisGrid>
          <axisLabel xml:lang="zh_CN" />
          <markers xml:lang="zh_CN" />
          <numberFormat xml:lang="zh_CN">
            <general precision="3" show-trailing-zeros="false" radix="dec" zero-threshold="15" imaginary-value="i" exponential-threshold="3" xml:lang="zh_CN" />
          </numberFormat>
          <xyDomain scale-type="linear" auto-scale="true" xml:lang="zh_CN">
            <startValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </startValue>
            <endValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </endValue>
          </xyDomain>
        </yAxis>
        <zAxis rank="1" start="-25" end="25" xml:lang="zh_CN">
          <axisLine position="origin" positionticmark="5" legendWidth="0" xml:lang="zh_CN" />
          <axisGrid xml:lang="zh_CN">
            <gridFrequency xml:lang="zh_CN">11</gridFrequency>
            <gridLabels display="true" xml:lang="zh_CN" />
            <gridLines xml:lang="zh_CN" />
            <tickMarks display="true" xml:lang="zh_CN" />
          </axisGrid>
          <axisLabel xml:lang="zh_CN" />
          <markers xml:lang="zh_CN" />
          <numberFormat xml:lang="zh_CN">
            <general precision="3" show-trailing-zeros="false" radix="dec" zero-threshold="15" imaginary-value="i" exponential-threshold="3" xml:lang="zh_CN" />
          </numberFormat>
          <zDomain scale-type="linear" auto-scale="true" xml:lang="zh_CN">
            <startValue xml:lang="zh_CN" resultRef="21">
              <real xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50">-25</real>
            </startValue>
            <endValue xml:lang="zh_CN" resultRef="22">
              <real xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50">25</real>
            </endValue>
          </zDomain>
        </zAxis>
      </axes>
      <contour color="#FF000000" show-lables="false" resultRef="23" xml:lang="zh_CN" />
      <graph-size width="192" height="192" xml:lang="zh_CN" />
      <plotEquation xml:lang="zh_CN">
        <math xml:lang="zh_CN">
          <id labels="VARIABLE" xml:space="preserve" xml:lang="zh_CN" label-is-contextual="true" xmlns="http://schemas.mathsoft.com/math50">F</id>
        </math>
        <math xml:lang="zh_CN">
          <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
        </math>
      </plotEquation>
    </contourPlot>
  </plot>
</region>

4. 通过改变 Y 轴刻度线放大奇点。

单击复制此表达式

<region id="ID0ESO5QB" actualWidth="284.51999999999953" actualHeight="243.03333333333336" top="595.2" left="19.200000000000003" xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/worksheet50">
  <plot background-type="transparent" xml:lang="zh_CN">
    <contourPlot xml:lang="zh_CN">
      <axes xml:lang="zh_CN">
        <xAxis rank="1" legend-position="PlotBoundaryBottom" start="-10" end="10" xml:lang="zh_CN">
          <axisLine position="ticknumberlock" positionticmark="0" legendWidth="0" xml:lang="zh_CN" />
          <axisGrid xml:lang="zh_CN">
            <gridFrequency xml:lang="zh_CN">11</gridFrequency>
            <gridLabels display="true" xml:lang="zh_CN" />
            <gridLines xml:lang="zh_CN" />
            <tickMarks display="true" xml:lang="zh_CN" />
          </axisGrid>
          <axisLabel xml:lang="zh_CN" />
          <markers xml:lang="zh_CN" />
          <numberFormat xml:lang="zh_CN">
            <general precision="3" show-trailing-zeros="false" radix="dec" zero-threshold="15" imaginary-value="i" exponential-threshold="3" xml:lang="zh_CN" />
          </numberFormat>
          <xyDomain scale-type="linear" auto-scale="true" xml:lang="zh_CN">
            <startValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </startValue>
            <endValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </endValue>
          </xyDomain>
        </xAxis>
        <yAxis rank="1" legend-position="PlotBoundaryLeft" start="-0.1" end="0.1" xml:lang="zh_CN">
          <axisLine position="ticknumberlock" positionticmark="0" legendWidth="0" xml:lang="zh_CN" />
          <axisGrid xml:lang="zh_CN">
            <gridFrequency xml:lang="zh_CN">11</gridFrequency>
            <gridLabels display="true" xml:lang="zh_CN" />
            <gridLines xml:lang="zh_CN" />
            <tickMarks display="true" xml:lang="zh_CN" />
          </axisGrid>
          <axisLabel xml:lang="zh_CN" />
          <markers xml:lang="zh_CN" />
          <numberFormat xml:lang="zh_CN">
            <general precision="3" show-trailing-zeros="false" radix="dec" zero-threshold="15" imaginary-value="i" exponential-threshold="3" xml:lang="zh_CN" />
          </numberFormat>
          <xyDomain scale-type="linear" auto-scale="true" xml:lang="zh_CN">
            <startValue xml:lang="zh_CN" resultRef="24">
              <real xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50">-0.1</real>
            </startValue>
            <endValue xml:lang="zh_CN" resultRef="25">
              <real xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50">0.1</real>
            </endValue>
          </xyDomain>
        </yAxis>
        <zAxis rank="1" start="-25" end="25" xml:lang="zh_CN">
          <axisLine position="origin" positionticmark="5" legendWidth="0" xml:lang="zh_CN" />
          <axisGrid xml:lang="zh_CN">
            <gridFrequency xml:lang="zh_CN">11</gridFrequency>
            <gridLabels display="true" xml:lang="zh_CN" />
            <gridLines xml:lang="zh_CN" />
            <tickMarks display="true" xml:lang="zh_CN" />
          </axisGrid>
          <axisLabel xml:lang="zh_CN" />
          <markers xml:lang="zh_CN" />
          <numberFormat xml:lang="zh_CN">
            <general precision="3" show-trailing-zeros="false" radix="dec" zero-threshold="15" imaginary-value="i" exponential-threshold="3" xml:lang="zh_CN" />
          </numberFormat>
          <zDomain scale-type="linear" auto-scale="true" xml:lang="zh_CN">
            <startValue xml:lang="zh_CN" resultRef="26">
              <real xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50">-25</real>
            </startValue>
            <endValue xml:lang="zh_CN" resultRef="27">
              <real xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50">25</real>
            </endValue>
          </zDomain>
        </zAxis>
      </axes>
      <contour color="#FF000000" show-lables="false" resultRef="28" xml:lang="zh_CN" />
      <graph-size width="212.99999999999955" height="190" xml:lang="zh_CN" />
      <plotEquation xml:lang="zh_CN">
        <math xml:lang="zh_CN">
          <id labels="VARIABLE" xml:space="preserve" xml:lang="zh_CN" label-is-contextual="true" xmlns="http://schemas.mathsoft.com/math50">F</id>
        </math>
        <math xml:lang="zh_CN">
          <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
        </math>
      </plotEquation>
    </contourPlot>
  </plot>
</region>

红色和蓝色区域代表了 Z 轴的值超出 -25 和 +25 范围的区域。

5. 通过删除用户定义的全部三个刻度值来恢复默认 Z 轴的值。

单击复制此表达式

<region id="ID0EDR5QB" actualWidth="284.51999999999953" actualHeight="243.03333333333336" top="883.20000000000016" left="19.200000000000003" xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/worksheet50">
  <plot background-type="transparent" xml:lang="zh_CN">
    <contourPlot xml:lang="zh_CN">
      <axes xml:lang="zh_CN">
        <xAxis rank="1" legend-position="PlotBoundaryBottom" start="-10" end="10" xml:lang="zh_CN">
          <axisLine position="ticknumberlock" positionticmark="0" legendWidth="0" xml:lang="zh_CN" />
          <axisGrid xml:lang="zh_CN">
            <gridFrequency xml:lang="zh_CN">11</gridFrequency>
            <gridLabels display="true" xml:lang="zh_CN" />
            <gridLines xml:lang="zh_CN" />
            <tickMarks display="true" xml:lang="zh_CN" />
          </axisGrid>
          <axisLabel xml:lang="zh_CN" />
          <markers xml:lang="zh_CN" />
          <numberFormat xml:lang="zh_CN">
            <general precision="3" show-trailing-zeros="false" radix="dec" zero-threshold="15" imaginary-value="i" exponential-threshold="3" xml:lang="zh_CN" />
          </numberFormat>
          <xyDomain scale-type="linear" auto-scale="true" xml:lang="zh_CN">
            <startValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </startValue>
            <endValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </endValue>
          </xyDomain>
        </xAxis>
        <yAxis rank="1" legend-position="PlotBoundaryLeft" start="-0.1" end="0.1" xml:lang="zh_CN">
          <axisLine position="ticknumberlock" positionticmark="0" legendWidth="0" xml:lang="zh_CN" />
          <axisGrid xml:lang="zh_CN">
            <gridFrequency xml:lang="zh_CN">11</gridFrequency>
            <gridLabels display="true" xml:lang="zh_CN" />
            <gridLines xml:lang="zh_CN" />
            <tickMarks display="true" xml:lang="zh_CN" />
          </axisGrid>
          <axisLabel xml:lang="zh_CN" />
          <markers xml:lang="zh_CN" />
          <numberFormat xml:lang="zh_CN">
            <general precision="3" show-trailing-zeros="false" radix="dec" zero-threshold="15" imaginary-value="i" exponential-threshold="3" xml:lang="zh_CN" />
          </numberFormat>
          <xyDomain scale-type="linear" auto-scale="true" xml:lang="zh_CN">
            <startValue xml:lang="zh_CN" resultRef="29">
              <real xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50">-0.1</real>
            </startValue>
            <endValue xml:lang="zh_CN" resultRef="30">
              <real xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50">0.1</real>
            </endValue>
          </xyDomain>
        </yAxis>
        <zAxis rank="1" start="-3200" end="3200" xml:lang="zh_CN">
          <axisLine position="origin" positionticmark="5" legendWidth="0" xml:lang="zh_CN" />
          <axisGrid xml:lang="zh_CN">
            <gridFrequency xml:lang="zh_CN">9</gridFrequency>
            <gridLabels display="true" xml:lang="zh_CN" />
            <gridLines xml:lang="zh_CN" />
            <tickMarks display="true" xml:lang="zh_CN" />
          </axisGrid>
          <axisLabel xml:lang="zh_CN" />
          <markers xml:lang="zh_CN" />
          <numberFormat xml:lang="zh_CN">
            <general precision="3" show-trailing-zeros="false" radix="dec" zero-threshold="15" imaginary-value="i" exponential-threshold="3" xml:lang="zh_CN" />
          </numberFormat>
          <zDomain scale-type="linear" auto-scale="true" xml:lang="zh_CN">
            <startValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </startValue>
            <endValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </endValue>
          </zDomain>
        </zAxis>
      </axes>
      <contour color="#FF000000" show-lables="false" resultRef="31" xml:lang="zh_CN" />
      <graph-size width="212.99999999999955" height="190" xml:lang="zh_CN" />
      <plotEquation xml:lang="zh_CN">
        <math xml:lang="zh_CN">
          <id labels="VARIABLE" xml:space="preserve" xml:lang="zh_CN" label-is-contextual="true" xmlns="http://schemas.mathsoft.com/math50">F</id>
        </math>
        <math xml:lang="zh_CN">
          <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
        </math>
      </plotEquation>
    </contourPlot>
  </plot>
</region>

6. 通过设置 Y 轴最小刻度值为零来查看绘图的上部分。

单击复制此表达式

<region id="ID0EYS5QB" actualWidth="284.51999999999953" actualHeight="243.03333333333336" top="1152.0000000000002" left="19.200000000000003" xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/worksheet50">
  <plot background-type="transparent" xml:lang="zh_CN">
    <contourPlot xml:lang="zh_CN">
      <axes xml:lang="zh_CN">
        <xAxis rank="1" legend-position="PlotBoundaryBottom" start="-10" end="10" xml:lang="zh_CN">
          <axisLine position="ticknumberlock" positionticmark="0" legendWidth="0" xml:lang="zh_CN" />
          <axisGrid xml:lang="zh_CN">
            <gridFrequency xml:lang="zh_CN">11</gridFrequency>
            <gridLabels display="true" xml:lang="zh_CN" />
            <gridLines xml:lang="zh_CN" />
            <tickMarks display="true" xml:lang="zh_CN" />
          </axisGrid>
          <axisLabel xml:lang="zh_CN" />
          <markers xml:lang="zh_CN" />
          <numberFormat xml:lang="zh_CN">
            <general precision="3" show-trailing-zeros="false" radix="dec" zero-threshold="15" imaginary-value="i" exponential-threshold="3" xml:lang="zh_CN" />
          </numberFormat>
          <xyDomain scale-type="linear" auto-scale="true" xml:lang="zh_CN">
            <startValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </startValue>
            <endValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </endValue>
          </xyDomain>
        </xAxis>
        <yAxis rank="1" legend-position="PlotBoundaryLeft" start="0" end="0.1" xml:lang="zh_CN">
          <axisLine position="ticknumberlock" positionticmark="0" legendWidth="0" xml:lang="zh_CN" />
          <axisGrid xml:lang="zh_CN">
            <gridFrequency xml:lang="zh_CN">11</gridFrequency>
            <gridLabels display="true" xml:lang="zh_CN" />
            <gridLines xml:lang="zh_CN" />
            <tickMarks display="true" xml:lang="zh_CN" />
          </axisGrid>
          <axisLabel xml:lang="zh_CN" />
          <markers xml:lang="zh_CN" />
          <numberFormat xml:lang="zh_CN">
            <general precision="3" show-trailing-zeros="false" radix="dec" zero-threshold="15" imaginary-value="i" exponential-threshold="3" xml:lang="zh_CN" />
          </numberFormat>
          <xyDomain scale-type="linear" auto-scale="true" xml:lang="zh_CN">
            <startValue xml:lang="zh_CN" resultRef="32">
              <real xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50">0</real>
            </startValue>
            <endValue xml:lang="zh_CN" resultRef="33">
              <real xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50">0.1</real>
            </endValue>
          </xyDomain>
        </yAxis>
        <zAxis rank="1" start="-32" end="32" xml:lang="zh_CN">
          <axisLine position="origin" positionticmark="5" legendWidth="0" xml:lang="zh_CN" />
          <axisGrid xml:lang="zh_CN">
            <gridFrequency xml:lang="zh_CN">11</gridFrequency>
            <gridLabels display="true" xml:lang="zh_CN" />
            <gridLines xml:lang="zh_CN" />
            <tickMarks display="true" xml:lang="zh_CN" />
          </axisGrid>
          <axisLabel xml:lang="zh_CN" />
          <markers xml:lang="zh_CN" />
          <numberFormat xml:lang="zh_CN">
            <general precision="3" show-trailing-zeros="false" radix="dec" zero-threshold="15" imaginary-value="i" exponential-threshold="3" xml:lang="zh_CN" />
          </numberFormat>
          <zDomain scale-type="linear" auto-scale="true" xml:lang="zh_CN">
            <startValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </startValue>
            <endValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </endValue>
          </zDomain>
        </zAxis>
      </axes>
      <contour color="#FF000000" show-lables="false" resultRef="34" xml:lang="zh_CN" />
      <graph-size width="212.99999999999955" height="190" xml:lang="zh_CN" />
      <plotEquation xml:lang="zh_CN">
        <math xml:lang="zh_CN">
          <id labels="VARIABLE" xml:space="preserve" xml:lang="zh_CN" label-is-contextual="true" xmlns="http://schemas.mathsoft.com/math50">F</id>
        </math>
        <math xml:lang="zh_CN">
          <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
        </math>
      </plotEquation>
    </contourPlot>
  </plot>
</region>

由于一奇点位于 y=0 处，因此等值线图无法计算数据。

7. 将 Y 轴的更低刻度值设成稍微比零小的值。

单击复制此表达式

<region id="ID0EPV5QB" actualWidth="284.51999999999953" actualHeight="243.03333333333336" top="1440.0000000000002" left="19.200000000000003" xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/worksheet50">
  <plot background-type="transparent" xml:lang="zh_CN">
    <contourPlot xml:lang="zh_CN">
      <axes xml:lang="zh_CN">
        <xAxis rank="1" legend-position="PlotBoundaryBottom" start="-10" end="10" xml:lang="zh_CN">
          <axisLine position="ticknumberlock" positionticmark="0" legendWidth="0" xml:lang="zh_CN" />
          <axisGrid xml:lang="zh_CN">
            <gridFrequency xml:lang="zh_CN">11</gridFrequency>
            <gridLabels display="true" xml:lang="zh_CN" />
            <gridLines xml:lang="zh_CN" />
            <tickMarks display="true" xml:lang="zh_CN" />
          </axisGrid>
          <axisLabel xml:lang="zh_CN" />
          <markers xml:lang="zh_CN" />
          <numberFormat xml:lang="zh_CN">
            <general precision="3" show-trailing-zeros="false" radix="dec" zero-threshold="15" imaginary-value="i" exponential-threshold="3" xml:lang="zh_CN" />
          </numberFormat>
          <xyDomain scale-type="linear" auto-scale="true" xml:lang="zh_CN">
            <startValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </startValue>
            <endValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </endValue>
          </xyDomain>
        </xAxis>
        <yAxis rank="1" legend-position="PlotBoundaryLeft" start="-0.01" end="0.1" xml:lang="zh_CN">
          <axisLine position="ticknumberlock" positionticmark="0" legendWidth="0" xml:lang="zh_CN" />
          <axisGrid xml:lang="zh_CN">
            <gridFrequency xml:lang="zh_CN">12</gridFrequency>
            <gridLabels display="true" xml:lang="zh_CN" />
            <gridLines xml:lang="zh_CN" />
            <tickMarks display="true" xml:lang="zh_CN" />
          </axisGrid>
          <axisLabel xml:lang="zh_CN" />
          <markers xml:lang="zh_CN" />
          <numberFormat xml:lang="zh_CN">
            <general precision="3" show-trailing-zeros="false" radix="dec" zero-threshold="15" imaginary-value="i" exponential-threshold="3" xml:lang="zh_CN" />
          </numberFormat>
          <xyDomain scale-type="linear" auto-scale="true" xml:lang="zh_CN">
            <startValue xml:lang="zh_CN" resultRef="35">
              <real xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50">-0.01</real>
            </startValue>
            <endValue xml:lang="zh_CN" resultRef="36">
              <real xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50">0.1</real>
            </endValue>
          </xyDomain>
        </yAxis>
        <zAxis rank="1" start="-7500" end="7500" xml:lang="zh_CN">
          <axisLine position="origin" positionticmark="5" legendWidth="0" xml:lang="zh_CN" />
          <axisGrid xml:lang="zh_CN">
            <gridFrequency xml:lang="zh_CN">11</gridFrequency>
            <gridLabels display="true" xml:lang="zh_CN" />
            <gridLines xml:lang="zh_CN" />
            <tickMarks display="true" xml:lang="zh_CN" />
          </axisGrid>
          <axisLabel xml:lang="zh_CN" />
          <markers xml:lang="zh_CN" />
          <numberFormat xml:lang="zh_CN">
            <general precision="3" show-trailing-zeros="false" radix="dec" zero-threshold="15" imaginary-value="i" exponential-threshold="3" xml:lang="zh_CN" />
          </numberFormat>
          <zDomain scale-type="linear" auto-scale="true" xml:lang="zh_CN">
            <startValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </startValue>
            <endValue xml:lang="zh_CN">
              <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
            </endValue>
          </zDomain>
        </zAxis>
      </axes>
      <contour color="#FF000000" show-lables="false" resultRef="37" xml:lang="zh_CN" />
      <graph-size width="212.99999999999955" height="190" xml:lang="zh_CN" />
      <plotEquation xml:lang="zh_CN">
        <math xml:lang="zh_CN">
          <id labels="VARIABLE" xml:space="preserve" xml:lang="zh_CN" label-is-contextual="true" xmlns="http://schemas.mathsoft.com/math50">F</id>
        </math>
        <math xml:lang="zh_CN">
          <placeholder xml:lang="zh_CN" xmlns="http://schemas.mathsoft.com/math50" />
        </math>
      </plotEquation>
    </contourPlot>
  </plot>
</region>

等值线图可计算数据。