Esempio: grafici a curve di livello con singolarità

Grafici > Grafici a curve di livello > Esempio: grafici a curve di livello con singolarità

Esempio: grafici a curve di livello con singolarità

1. Definire una funzione di due variabili con una singolarità nota.

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2. Tracciare F come grafico a curve di livello.

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3. Per l'asse z impostare l'intervallo da -25 a 25.

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4. Eseguire lo zoom avanti sulla singolarità modificando le tacche dell'asse y:

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Le aree rosse e blu rappresentano le regioni in cui l'asse z assume valori non compresi tra -25 e +25.

5. Ripristinare i valori di default per l'asse z eliminando tutti i valori delle tacche definiti dall'utente.

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6. Visualizzare la metà superiore del grafico impostando su zero la tacca minima dell'asse y.

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Il grafico a curve di livello non riesce a calcolare i dati perché è presente una singolarità per y=0.

7. Impostare il valore della tacca inferiore dell'asse y su un valore lievemente inferiore a zero.

Fare clic per copiare questa espressione

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

Il grafico a curve di livello ora è in grado di calcolare i dati.