Esempio: superficie di risposta di secondo ordine

Funzioni > Pianificazione degli esperimenti > Analisi della regressione > Esempio: superficie di risposta di secondo ordine

Utilizzare le funzioni boxwilson, polyfitc e polyfit per pianificare un esperimento e creare un modello per il processo studiato. Utilizzare un blocco di soluzione per trovare il rendimento massimo predetto dal modello.

1. Definire una matrice di pianificazione boxwilson.

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2. Definire i valori reali per A (tempo di reazione in minuti) e B (temperatura in Fahrenheit), che sono le variabili naturali per il processo chimico studiato.

3. Chiamare la funzione doelabel per convertire i valori codificati della matrice di pianificazione nei valori reali delle variabili naturali.

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4. Registrare il rendimento del processo chimico per ogni esecuzione.

5. Chiamare polyfitc per eseguire una regressione polinomiale di secondo ordine con i valori codificati.

6. Estrarre i coefficienti di regressione dall'output di polyfitc.

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7. Creare una funzione di valori codificati che modelli la reazione chimica. Utilizzare questa funzione per determinare il rendimento per A=-1 e B=1.

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8. Chiamare polyfit per creare una funzione di valori reali che modelli la reazione chimica. Utilizzare questa funzione per prevedere il rendimento in t=80 min e T=170F.

Come previsto, il rendimento calcolato corrisponde a quello del passaggio 7.

9. Utilizzare un blocco di soluzione per trovare il rendimento minimo.

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10. Usare un grafico a curve di livello per il rendimento per t_max e T_max.

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Riferimenti

Montgomery, D.C., Design and Analysis of Experiments, 5th ed., John Wiley & Sons, New York, 2001, pp. 442.

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