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Chinese remainder theorem



x = crt(res,div) returns the scalar integer x that is congruent to each remainder in res for the corresponding divisor in div. x satisfies

mod(x,div) = res.

In other words, dividing x by each element of div leaves as remainder the corresponding element of res.


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Find a number that has a remainder of 2 when divided by 9, a remainder of 3 when divided by 10, and a remainder of 6 when divided by 11.

x = crt([2 3 6],[9 10 11])
x = 83

Use the mod function to verify the result.

ver = mod(x,[9 10 11])
ver = 1×3

     2     3     6

In a staggered pulse repetition frequency (PRF) radar system, the first PRF corresponds to 70 range bins and the second PRF corresponds to 85 range bins. The target is detected at bin 47 for the first PRF and bin 12 for the second PRF. Assuming each range bin is 50 meters, compute the target range from these two measurements.

idx = crt([47 12],[70 85]);
r = 50*idx
r = 30350

Input Arguments

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Remainder array, specified as a row vector of nonnegative integers. res must have the same number of elements as div.

Data Types: single | double

Divisor array, specified as a row vector of positive integers. div must have the same number of elements as res.

Data Types: single | double

Output Arguments

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Congruent integer, returned as a scalar.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Introduced in R2021a