Julia for MATLAB Users/Core Language/Language Fundamentals

Language Fundamentals

This page maps MATLAB functionality documented in the Language Fundamentals section of the MATLAB documentation to equivalent Julia (core language and/or package) functionality.

Another helpful resource is the noteworthy differences from MATLAB section of the Julia documentation.

Entering Commands

Related: Julia REPL

ans Most recent answer

Julia's ans is functionally basically identical, though note that it is available only at the REPL.

clc Clear Command Window

Ctrl+L is nearly equivalent in the Julia REPL, though it does not erase history; you can still scroll up to see the history of the session. You can also equivalently (on Linux/Mac) run the clear(1) command in shell mode, i.e. ;+clear.

save Command Window text to file

There doesn't appear to be an equivalent Julia REPL command.

format Set Command Window output display format

There is no drop-in equivalent in the Julia REPL or IJulia for globally setting the output format.

home Send cursor home

Ctrl+L is functionally equivalent in the Julia REPL.

iskeyword Determine whether input is MATLAB keyword

There doesn't appear to be an equivalent Julia command, but see Keywords in the Julia manual.

Matrices and Arrays

See Multi-dimensional Arrays in the Julia Manual.

zeros Create array of all zeros; ones Create array of all ones

Julia's zeros and ones are functionally equivalent. Note that the syntax for specifying the data type of the result is different, e.g. Julia: zeros(Int64, 3, 3) vs. MATLAB zeros(3,3, 'int64').

rand Uniformly distributed random numbers

See Julia's rand.

eye Identity matrix

In Julia to construct a numeric identity matrix, use something like Matrix(1.0I, 3, 3). Note that the symbol I is special in Julia; rather than representing a matrix, it is an instance of the UniformScaling operator so that in principle its use can be more efficient than the naive use of a dense matrix that happens to have 1's on the diagonal and zeros elsewhere.

horzcat Concatenate arrays horizontally

See Julia's hcat function

length Length of largest array dimension

Julia has a length function, however it does not operate the same way as Matlab's for multidimensional arrays. To get equivalent behavior to Matlab's length(X), use maximum(size(X)) in Julia.

ndims Number of array dimensions

In Julia, ndims is similar but not identical. For instance, Julia does not ignore singleton dimensions.

numel Number of array elements

In Julia, length is equivalent.

squeeze Remove singleton dimensions

Julia's dropdims function is similar though it requires the singleton dimension(s) to be specified explicitly.

end Terminate block of code, or indicate last array index

Julia's end is basically equivalent.

Operators and Elementary Operations

See Mathematical Operations and Elementary Functions in the Julia manual.

Logical Operations

Logical Operators: Short-circuit Logical operations with short-circuiting

find Find indices and values of nonzero elements

In Julia, findall provides similar functionality. See also findfirst, findlast, findnext and findprev.

Data Types

See Types in the Julia manual.