How Can You Efficiently Calculate x from y = log2(x)?

AI Thread Summary
To efficiently calculate x from the equation y = log2(x), the quickest method is to use the formula x = 2^y, which directly derives x from the known y value. This approach avoids iterative methods and significantly improves performance, making it suitable for applications where timing is critical. Implementing this solution in C++ can be done using built-in exponentiation functions for optimal efficiency. The discussion emphasizes the importance of minimizing steps in the calculation process. Overall, using the exponential function is the most effective strategy for this logarithmic equation.
macilak
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Hello All,

I have a very impotant question for you. Any help is appreciated.

Given is a logarithmical function: y = log2x (2 is the base) and the y value is known.
I have to find out what is the x value in the fewest steps possible. It can be made by giving sample values for x and applying to the function, but the performance (timing) is a key value, so the process must be very quick. The known solution is to split the curve to lines and shrink the range of possibilities.

Later on I have to translate the solution into C++ and apply it for calibration.

Many thanks in advance for your help!
 
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Are you constrained to solving the problem by iteration? You could just write x=2^y and use the built-in functions.
 

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