I have some data that I have interpolated with even spacing from measured data. I can integrate this between defined limits etc using trapz. However, I want to turn the problem on its head and find for what limit does the result of definite integral satisfy a condition. As an example:

x = linspace(0, 2*pi, 20);
y = sin(x);

lowLimIndex = 1;
upLimIndex = find(x>pi,1);
halfInt = trapz(x(lowLimIndex:upLimIndex),y(lowLimIndex:upLimIndex))
Or close enough to the known result of 2… But in my case, I effectively want to find the value of x that results in the integral = 2.
I could fit an equation to my data and use solve to solve it in symbolic mode I suppose…. Seems there ought to be a way to do this using the optimization tools though?

Any help appreciated!I have some data that I have interpolated with even spacing from measured data. I can integrate this between defined limits etc using trapz. However, I want to turn the problem on its head and find for what limit does the result of definite integral satisfy a condition. As an example:

x = linspace(0, 2*pi, 20);
y = sin(x);

lowLimIndex = 1;
upLimIndex = find(x>pi,1);
halfInt = trapz(x(lowLimIndex:upLimIndex),y(lowLimIndex:upLimIndex))
Or close enough to the known result of 2… But in my case, I effectively want to find the value of x that results in the integral = 2.
I could fit an equation to my data and use solve to solve it in symbolic mode I suppose…. Seems there ought to be a way to do this using the optimization tools though?

Any help appreciated! I have some data that I have interpolated with even spacing from measured data. I can integrate this between defined limits etc using trapz. However, I want to turn the problem on its head and find for what limit does the result of definite integral satisfy a condition. As an example:

x = linspace(0, 2*pi, 20);
y = sin(x);

lowLimIndex = 1;
upLimIndex = find(x>pi,1);
halfInt = trapz(x(lowLimIndex:upLimIndex),y(lowLimIndex:upLimIndex))
Or close enough to the known result of 2… But in my case, I effectively want to find the value of x that results in the integral = 2.
I could fit an equation to my data and use solve to solve it in symbolic mode I suppose…. Seems there ought to be a way to do this using the optimization tools though?

Any help appreciated! definite integral, optimization MATLAB Answers — New Questions

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