App Designer: Linking a equation to a Label, I want to show the changing values depending on the inputs given

I have a function as seen in the image. The parameter values in this function change according to the input values entered.

I want to see the values of each parameter on the function according to the input values entered.

I want to represent these values on an equation image or text. (The user will enter some inputs, and the parameter values will change. I want to see this parameter values in my screen when I enter the inputs) I tried to write the equation in App Designer using app.Label. But I couldn't. And also I wonder whether we can do it with "Interpreter" , "Latex" ? I would be very happy if you could help.

Thanks a lot :))

Answer 1

[surya venu]

Hi,

Here are the steps to do it:

1. Create Text Box for User Input:

• In App Designer, drag a 'Edit Field' component from the Layout palette onto your app window.
• Name this component appropriately, such as 'inputValue' or 'userInput', to reflect its purpose.

2. Design the Equation Display:

• Drag a 'Text Area' component from the Layout palette. This will hold the equation with placeholders for parameter values.
• Name this component 'equationDisplay' (or a similar name) for clarity.

3. Construct the Equation String:

• Within the callback function that gets executed when the user enters a value and presses a button (or triggers an update event), construct the equation string dynamically.
• Use string concatenation to combine the static equation parts with placeholders for the parameters.

Here's an illustrative example assuming the equation is F_H(S) = K / ((T_L * S + 1) * (T_1 * S + 1)) * (1 / (2 * zeta * wn^2)) * exp(-t * S):

function updateEquation(app)
  % Get user input from the edit field
  userInput = app.inputValue.Value;

  % Define parameter values (replace with your actual calculations based on userInput)
  K = ...; % Replace with calculation based on userInput
  T_L = ...; % Replace with calculation based on userInput
  T_1 = ...; % Replace with calculation based on userInput
  zeta = ...; % Replace with calculation based on userInput
  wn = ...; % Replace with calculation based on userInput
  t = ...; % Replace with calculation based on userInput

  % Construct the equation string with placeholders and calculated values
  equationStr = ['F_H(S) = ', num2str(K), ' / ((', num2str(T_L), ' * S + 1) * (', num2str(T_1), ' * S + 1)) * (1 / (2 * ', num2str(zeta), ' * ', num2str(wn), '^2)) * exp(-', num2str(t), ' * S)'];

  % Set the equation display text area with the constructed string
  app.equationDisplay.Value = equationStr;
end

4. Call the Callback Function:

• Link the callback function (e.g., updateEquation) to a button press event or any other appropriate trigger in your app.
• When the event occurs, the callback function will execute, update the equation string with the latest parameter values, and display it in the text area.

Hope it helps