MATLAB: Am I having so many errors

equationerrorfprintfintegerstring

The purpose of the code is to take the inputs and calculate the weight of something on a different planet. Here is the code:
    name = input('What is the name of the exoplanet? ', 's');
    massplanet = input( sprintf('What is the estimated mass of %s(kg)? ', name), 's');
    radius = input( sprintf('What is the estimated radius of %s(km)? ', name), 's');
    massspecimen = input('What is the mass of the specimen (kg)? ');
    %calculating acceleration due to gravity of other planet using:
    %G * mass / radius^2
    %G is a constant
    Accel_of_G_exo = ((6.67e-11) * massplanet) / radius^2 ;  
    %calculating weight of specimen using acceleration due to gravity of other
    %planet and mass of specimen
    Weight_exo = Accel_of_G_exo * massspecimen; 
    %trying to print the name of the planet as well as the variable Weight_exo
    fprintf('On %s, it would weigh about %f Newtons.',name, Weight_exo);
However, when I run the code, I am getting an error on the line where I try to define the variable 'Accel_of_G_exo'. I am assuming the variables 'massplanet' and 'radius' are stored as string types, therefore they can not be incorporated in an equation. Also, on the last line, I tried to print a statement that included the variables 'name' and 'Weight_exo', however, I do not think that I can use %s with fprintf. Thank you so much for the help. I am new to MATLAB and am still learning the program.

Best Answer

You need to str2double() the strings that hold the masses. Or just skip the 's' option of input() to read the values as numeric.
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