calculating x when y is > 0

4 vues (au cours des 30 derniers jours)
Gavin Seddon
Gavin Seddon le 13 Fév 2019
Commenté : Gavin Seddon le 14 Mar 2019
Hello
I have plotted a changing distance (d(x)) with time using cftool and calculated the function. Its derivative was calculated and this is v(x). when plotted with fplot the initial Y values are 0. I am calculating the x position at which this rises above the x axes (y>0). To do this i made v(x) equivalent to 1 (==1) and evluated x yet:
>>v(x)==1
ans =
(4119*x^2)/10000 - (1787*x)/5000 + 891/2500 ==1
>> eval x
x =
x
Will someone please help to calculate this? i can measure the x value directly. It is preferable to standardise this procedure.
GS.
  2 commentaires
Gavin Seddon
Gavin Seddon le 14 Fév 2019
Hello, I tried
solve (x)
ans =
0
does this help?
GS.
madhan ravi
madhan ravi le 14 Fév 2019
Are you asking or stating?

Connectez-vous pour commenter.

Réponse acceptée

Walter Roberson
Walter Roberson le 14 Fév 2019
solve(v(x)==1,x)
  16 commentaires
Walter Roberson
Walter Roberson le 13 Mar 2019
Do you mean that the second column of your table contains x values ? If so then
YourTable.NewThirdColumn = double( subs( v, x, YourTable.{:,2}));
Gavin Seddon
Gavin Seddon le 14 Mar 2019
Hello,
mytable.NewThirdColumn = double( subs( v, x, MyTable.(2)));
was the command used and yes indeed it produced a third column.
The numbers revealed indicate the method I tried previously was indeterminate. Thank you
GS.

Connectez-vous pour commenter.

Plus de réponses (0)

Catégories

En savoir plus sur Loops and Conditional Statements dans Help Center et File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by