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.

Remember that it is recommended to read the noteworthy differences from MATLAB section of the Julia documentation.

Entering Commands

Related: Julia REPL

• ans Most recent answer
• clc Clear Command Window
• save Command Window text to file
• format Set Command Window output display format
• home Send cursor home
• iskeyword Determine whether input is MATLAB keyword
• more Control paged output for Command Window

Matrices and Arrays

• zeros Create array of all zeros
• ones Create array of all ones
• rand Uniformly distributed random numbers
• true Logical 1 (true)
• false Logical 0 (false)
• eye Identity matrix
• diag Create diagonal matrix or get diagonal elements of matrix
• blkdiag Construct block diagonal matrix from input arguments
• cat Concatenate arrays along specified dimension
• horzcat Concatenate arrays horizontally
• vertcat Concatenate arrays vertically
• repelem Repeat copies of array elements
• repmat Repeat copies of array
• linspace Generate linearly spaced vector
• logspace Generate logarithmically spaced vector
• freqspace Frequency spacing for frequency response
• meshgrid 2-D and 3-D grids
• ndgrid Rectangular grid in N-D space
• length Length of largest array dimension
• size Array size
• ndims Number of array dimensions
• numel Number of array elements
• isscalar Determine whether input is scalar
• isvector Determine whether input is vector
• ismatrix Determine whether input is matrix
• isrow Determine whether input is row vector
• iscolumn Determine whether input is column vector
• isempty Determine whether array is empty
• sort Sort array elements
• sortrows Sort rows of matrix or table
• issorted Determine if array is sorted
• issortedrows Determine if matrix or table rows are sorted
• topkrows Top rows in sorted order
• flip Flip order of elements
• fliplr Flip array left to right
• flipud Flip array up to down
• rot90 Rotate array 90 degrees
• transpose Transpose vector or matrix
• ctranspose Complex conjugate transpose
• permute Rearrange dimensions of N-D array
• ipermute Inverse permute dimensions of N-D array
• circshift Shift array circularly
• shiftdim Shift dimensions
• reshape Reshape array
• squeeze Remove singleton dimensions
• colon Vector creation, array subscripting, and for-loop iteration
• end Terminate block of code, or indicate last array index
• ind2sub Subscripts from linear index
• sub2ind Convert subscripts to linear indices

Operators and Elementary Operations

See Mathematical Operations and Elementary Functions in the Julia manual.

Arithmetic

• plus Addition
• uplus Unary plus
• minus Subtraction
• uminus Unary minus
• times Element-wise multiplication
• rdivide Right array division
• ldivide Left array division
• power Element-wise power
• mtimes Matrix Multiplication
• mrdivide Solve systems of linear equations xA = B for x
• mldivide Solve systems of linear equations Ax = B for x
• mpower Matrix power
• cumprod Cumulative product
• cumsum Cumulative sum
• diff Differences and Approximate Derivatives
• movsum Moving sum
• prod Product of array elements
• sum Sum of array elements
• ceil Round toward positive infinity
• fix Round toward zero
• floor Round toward negative infinity
• idivide Integer division with rounding option
• mod Remainder after division (modulo operation)
• rem Remainder after division
• round Round to nearest decimal or integer
• bsxfun Apply element-wise operation to two arrays with implicit expansion enabled

Relational Operations

• eq Determine equality
• ge Determine greater than or equal to
• gt Determine greater than
• le Determine less than or equal to
• lt Determine less than
• ne Determine inequality
• isequal Determine array equality
• isequaln Determine array equality, treating NaN values as equal

Logical Operations

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

• and Find logical AND
• not Find logical NOT
• or Find logical OR
• xor Find logical exclusive-OR
• all Determine if all array elements are nonzero or true
• any Determine if any array elements are nonzero
• false Logical 0 (false)
• find Find indices and values of nonzero elements
• islogical Determine if input is logical array
• logical Convert numeric values to logicals
• true Logical 1 (true)

Set Operations

• intersect Set intersection of two arrays
• ismember Array elements that are members of set array
• ismembertol Members of set within tolerance
• issorted Determine if array is sorted
• setdiff Set difference of two arrays
• setxor Set exclusive OR of two arrays
• union Set union of two arrays
• unique Unique values in array
• uniquetol Unique values within tolerance
• join Combine two tables or timetables by rows using key variables
• innerjoin Inner join between two tables or timetables
• outerjoin Outer join between two tables or timetables

Bit-Wise Operations

• bitand Bit-wise AND
• bitcmp Bit-wise complement
• bitget Get bit at specified position
• bitor Bit-wise OR
• bitset Set bit at specific location
• bitshift Shift bits specified number of places
• bitxor Bit-wise XOR
• swapbytes Swap byte ordering

Data Types

See Types in the Julia manual.

Numeric Types

• double Double-precision arrays
• single Single-precision arrays
• int8 8-bit signed integer arrays
• int16 16-bit signed integer arrays
• int32 32-bit signed integer arrays
• int64 64-bit signed integer arrays
• uint8 8-bit unsigned integer arrays
• uint16 16-bit unsigned integer arrays
• uint32 32-bit unsigned integer arrays
• uint64 64-bit unsigned integer arrays
• cast Cast variable to different data type
• typecast Convert data types without changing underlying data
• isinteger Determine if input is integer array
• isfloat Determine if input is floating-point array
• isnumeric Determine if input is numeric array
• isreal Determine whether array is real
• isfinite Array elements that are finite
• isinf Array elements that are infinite
• isnan Array elements that are NaN
• eps Floating-point relative accuracy
• flintmax Largest consecutive integer in floating-point format
• Inf Infinity
• intmax Largest value of specified integer type
• intmin Smallest value of specified integer type
• NaN Not-a-Number
• realmax Largest positive floating-point number
• realmin Smallest positive normalized floating-point number

Characters and Strings

• string String array
• strings Create array of strings with no characters
• join Combine strings
• char Character array
• cellstr Convert to cell array of character vectors
• blanks Create character array of blanks
• newline Create newline character
• compose Convert data into formatted string array
• sprintf Format data into string
• strcat Concatenate strings horizontally
• convertCharsToStrings Convert character arrays to string arrays, leaving other arrays unaltered
• convertStringsToChars Convert string arrays to character arrays, leaving other arrays unaltered
• ischar Determine if input is character array
• iscellstr Determine if input is cell array of character vectors
• isstring Determine if input is string array
• isStringScalar Determine if input is string array with one element
• strlength Length of strings in string array
• isstrprop Determine if string is of specified category
• isletter Determine which characters are letters
• isspace Determine which characters are space characters
• contains Determine if pattern is in string
• count Count occurrences of pattern in string
• endsWith Determine if string ends with pattern
• startsWith Determine if string starts with pattern
• strfind Find one string within another
• sscanf Read formatted data from string
• replace Find and replace substrings in string array
• replaceBetween Replace substrings identified by indicators that mark their starts and ends
• strrep Find and replace substring
• join Combine strings
• split Split strings in string array
• splitlines Split string at newline characters
• strjoin Join text in array
• strsplit Split string at specified delimiter
• strtok Selected parts of string
• erase Delete substrings within strings
• eraseBetween Delete substrings between indicators that mark starts and ends of substrings
• extractAfter Extract substring after specified position
• extractBefore Extract substring before specified position
• extractBetween Extract substrings between indicators that mark starts and ends of substrings
• insertAfter Insert string after specified substring
• insertBefore Insert string before specified substring
• pad Add leading or trailing characters to strings
• strip Remove leading and trailing characters from string
• lower Convert string to lowercase
• upper Convert string to uppercase
• reverse Reverse order of characters in string
• deblank Remove trailing whitespace from end of string or character array
• strtrim Remove leading and trailing whitespace from string array or character array
• strjust Justify string or character array
• strcmp Compare strings
• strcmpi Compare strings (case insensitive)
• strncmp Compare first n characters of strings (case sensitive)
• strncmpi Compare first n characters of strings (case insensitive)
• regexp Match regular expression (case sensitive)
• regexpi Match regular expression (case insensitive)
• regexprep Replace text using regular expression
• regexptranslate Translate text into regular expression

Dates and Time

• datetime Arrays that represent points in time
• NaT Not-a-Time
• years Duration in years
• days Duration in days
• hours Duration in hours
• minutes Duration in minutes
• seconds Duration in seconds
• milliseconds Duration in milliseconds
• duration Lengths of time in fixed-length units
• calyears Calendar duration in years
• calquarters Calendar duration in quarters
• calmonths Calendar duration in months
• calweeks Calendar duration in weeks
• caldays Calendar duration in days
• calendarDuration Lengths of time in variable-length calendar units
• year Year number
• quarter Quarter number
• month Month number and name
• week Week number
• day Day number or name
• hour Hour number
• minute Minute number
• second Second number
• ymd Year, month, and day numbers of datetime
• hms Hour, minute, and second numbers of duration
• split Split calendar duration into numeric and duration units
• time Convert time of calendar duration to duration
• timeofday Elapsed time since midnight for datetimes
• isdatetime Determine if input is datetime array
• isduration Determine if input is duration array
• iscalendarduration Determine if input is calendar duration array
• isnat Determine NaT (Not-a-Time) elements
• isdst Determine daylight saving time elements
• isweekend Determine weekend elements
• timezones List time zones
• tzoffset Time zone offset from UTC
• between Calendar math differences
• caldiff Calendar math successive differences
• dateshift Shift date or generate sequence of dates and time
• isbetween Determine elements within date and time interval
• datenum Convert date and time to serial date number
• datevec Convert date and time to vector of components
• exceltime Convert MATLAB datetime to Excel date number
• juliandate Convert MATLAB datetime to Julian date
• posixtime Convert MATLAB datetime to POSIX time
• yyyymmdd Convert MATLAB datetime to YYYYMMDD numeric value
• addtodate Modify date number by field
• char Character array
• string String array
• datestr Convert date and time to string format
• now Current date and time as serial date number
• clock Current date and time as date vector
• date Current date string
• calendar Calendar for specified month
• eomday Last day of month
• weekday Day of week
• etime Time elapsed between date vectors

Categorical Arrays

• categorical Array that contains values assigned to categories
• iscategorical Determine whether input is categorical array
• discretize Group data into bins or categories
• categories Categories of categorical array
• iscategory Test for categorical array categories
• isordinal Determine whether input is ordinal categorical array
• isprotected Determine whether categories of categorical array are protected
• addcats Add categories to categorical array
• mergecats Merge categories in categorical array
• removecats Remove categories from categorical array
• renamecats Rename categories in categorical array
• reordercats Reorder categories in categorical array
• setcats Set categories in categorical array
• summary Print summary of table, timetable, or categorical array
• countcats Count occurrences of categorical array elements by category
• isundefined Find undefined elements in categorical array

Tables

• table Table array with named variables that can contain different types
• array2table Convert homogeneous array to table
• cell2table Convert cell array to table
• struct2table Convert structure array to table
• table2array Convert table to homogeneous array
• table2cell Convert table to cell array
• table2struct Convert table to structure array
• table2timetable Convert table to timetable
• timetable2table Convert timetable to table
• readtable Create table from file
• writetable Write table to file
• detectImportOptions Create import options based on file content
• getvaropts Get variable import options
• setvaropts Set variable import options
• setvartype Set variable data types
• head Get top rows of table, timetable, or tall array
• tail Get bottom rows of table, timetable, or tall array
• summary Print summary of table, timetable, or categorical array
• height Number of table rows
• width Number of table variables
• istable Determine whether input is table
• sortrows Sort rows of matrix or table
• unique Unique values in array
• issortedrows Determine if matrix or table rows are sorted
• topkrows Top rows in sorted order
• addvars Add variables to table or timetable
• movevars Move variables in table or timetable
• removevars Delete variables from table or timetable
• splitvars Split multicolumn variables in table or timetable
• mergevars Combine table or timetable variables into multicolumn variable
• vartype Subscript into table or timetable by variable type
• rows2vars Reorient table or timetable so that rows become variables
• stack Stack data from multiple variables into single variable
• unstack Unstack data from single variable into multiple variables
• inner2outer Invert nested table-in-table hierarchy in tables or timetables
• join Combine two tables or timetables by rows using key variables
• innerjoin Inner join between two tables or timetables
• outerjoin Outer join between two tables or timetables
• union Set union of two arrays
• intersect Set intersection of two arrays
• ismember Array elements that are members of set array
• setdiff Set difference of two arrays
• setxor Set exclusive OR of two arrays
• ismissing Find missing values
• standardizeMissing Insert standard missing values
• rmmissing Remove missing entries
• fillmissing Fill missing values
• varfun Apply function to table or timetable variables
• rowfun Apply function to table or timetable rows
• findgroups Find groups and return group numbers
• splitapply Split data into groups and apply function
• groupsummary Group summary computations

Timetables

• timetable Timetable array with time-stamped rows and variables of different types
• retime Resample or aggregate data in timetable, and resolve duplicate or irregular times synchronize Synchronize timetables to common time vector, and resample or aggregate data from input * timetables
• lag Time-shift data in timetable
• table2timetable Convert table to timetable
• array2timetable Convert homogeneous array to timetable
• timetable2table Convert timetable to table
• istimetable Determine if input is timetable
• isregular Determine whether times in timetable are regular
• timerange Time range for timetable row subscripting
• withtol Time tolerance for timetable row subscripting
• vartype Subscript into table or timetable by variable type
• rmmissing Remove missing entries
• issorted Determine if array is sorted
• sortrows Sort rows of matrix or table
• unique Unique values in array

Structures

• struct Structure array
• fieldnames Field names of structure, or public fields of COM or Java object
• getfield Field of structure array
• isfield Determine whether input is structure array field
• isstruct Determine whether input is structure array
• orderfields Order fields of structure array
• rmfield Remove fields from structure
• setfield Assign values to structure array field
• arrayfun Apply function to each element of array
• structfun Apply function to each field of scalar structure
• table2struct Convert table to structure array
• struct2table Convert structure array to table
• cell2struct Convert cell array to structure array
• struct2cell Convert structure to cell array

Cell Arrays

• cell Cell array
• cell2mat Convert cell array to ordinary array of the underlying data type
• cell2struct Convert cell array to structure array
• cell2table Convert cell array to table
• celldisp Display cell array contents
• cellfun Apply function to each cell in cell array
• cellplot Graphically display structure of cell array
• cellstr Convert to cell array of character vectors
• iscell Determine whether input is cell array
• iscellstr Determine if input is cell array of character vectors
• mat2cell Convert array to cell array with potentially different sized cells
• num2cell Convert array to cell array with consistently sized cells
• strjoin Join text in array
• strsplit Split string at specified delimiter
• struct2cell Convert structure to cell array
• table2cell Convert table to cell array

Function Handles

• feval Evaluate function
• func2str Construct character vector from function handle
• str2func Construct function handle from character vector
• localfunctions Function handles to all local functions in MATLAB file
• functions Information about function handle

Map Containers

• containers.Map Object that maps values to unique keys
• isKey Determine if Map object contains key
• keys Return keys of Map object
• remove Delete key-value pairs from Map object
• values Return values of Map object

Time Series

Time Series Objects

• timeseries Create timeseries object
• addevent Add event to timeseries
• addsample Add data sample to timeseries object
• append Concatenate timeseries objects in time
• delevent Remove event from timeseries
• delsample Remove sample from timeseries object
• detrend Subtract mean or best-fit line from timeseries object
• filter Modify frequency content of timeseries objects
• idealfilter timeseries ideal filter
• plot Plot timeseries
• resample Resample timeseries time vector
• set Set timeseries properties
• setabstime Set timeseries times as date character vectors
• setinterpfunction Set default interpolation method for timeseries object
• setuniformtime Modify uniform timeseries time vector
• synchronize Synchronize and resample two timeseries objects using common time vector
• get Query timeseries properties
• getabstime Convert timeseries time vector to cell array
• getdatasamples Access timeseries data samples
• getdatasamplesize timeseries data sample size
• getinterpmethod timeseries interpolation method
• getqualitydesc timeseries data quality
• getsamples Subset of timeseries
• getsampleusingtime Subset of timeseries data
• gettsafteratevent Create timeseries at or after event
• gettsafterevent Create timeseries after event
• gettsatevent Create timeseries at event
• gettsbeforeatevent Create timeseries at or before event
• gettsbeforeevent Create timeseries before event
• gettsbetweenevents Create timeseries between events
• iqr Interquartile range of timeseries data
• max Maximum of timeseries data
• mean Mean of timeseries data
• median Median of timeseries data
• min Minimum of timeseries data
• std Standard deviation of timeseries data
• sum Sum of timeseries data
• var Variance of timeseries data

Time Series Collections

• tscollection Create tscollection object
• addsampletocollection Add sample to tscollection
• addts Add timeseries to tscollection
• delsamplefromcollection Delete sample from tscollection
• horzcat Horizontally concatenate tscollection objects
• removets Remove timeseries from tscollection
• resample Resample tscollection time vector
• set Set tscollection properties
• setabstime Set tscollection times as date character vectors
• settimeseriesnames Rename timeseries in tscollection
• vertcat Vertically concatenate tscollection objects
• get Query tscollection properties
• getabstime Convert tscollection time vector to cell array
• getsampleusingtime Subset of tscollection data
• gettimeseriesnames Names of timeseries in tscollection
• isempty Determine if tscollection is empty
• length Length of tscollection time vector
• size Size of tscollection

Time Series Events

• tsdata.event Create tsdata.event object
• findEvent Query tsdata.event by name
• get Query tsdata.event properties
• getTimeStr Query tsdata.event times
• set Set tsdata.event properties

Data Type Identification

• iscalendarduration Determine if input is calendar duration array
• iscategorical Determine whether input is categorical array
• iscell Determine whether input is cell array
• iscellstr Determine if input is cell array of character vectors
• ischar Determine if input is character array
• isdatetime Determine if input is datetime array
• isduration Determine if input is duration array
• isenum Determine if variable is enumeration
• isfloat Determine if input is floating-point array
• isgraphics True for valid graphics object handles
• isinteger Determine if input is integer array
• isjava Determine if input is Java object
• islogical Determine if input is logical array
• isnumeric Determine if input is numeric array
• isobject Determine if input is MATLAB object
• isreal Determine whether array is real
• isstring Determine if input is string array
• isstruct Determine whether input is structure array
• istable Determine whether input is table
• istimetable Determine if input is timetable
• is Detect state
• isa Determine if input is object of specified class
• class Determine class of object
• validateattributes Check validity of array
• whos List variables in workspace, with sizes and types

Data Type Conversion

• char Character array
• cellstr Convert to cell array of character vectors
• int2str Convert integers to characters
• mat2str Convert matrix to characters
• num2str Convert numbers to character array
• str2double Convert string to double precision value
• str2num Convert character array to numeric array
• native2unicode Convert numeric bytes to Unicode character representation
• unicode2native Convert Unicode character representation to numeric bytes
• base2dec Convert text representing number in base N to decimal number
• bin2dec Convert text representation of binary number to decimal number
• dec2base Convert decimal number to character vector representing base N number
• dec2bin Convert decimal number to character vector representing binary number
• dec2hex Convert decimal number to character vector representing hexadecimal number
• hex2dec Convert text representation of hexadecimal number to decimal number
• hex2num Convert IEEE hexadecimal string to double-precision number
• num2hex Convert singles and doubles to IEEE hexadecimal strings
• table2array Convert table to homogeneous array
• table2cell Convert table to cell array
• table2struct Convert table to structure array
• array2table Convert homogeneous array to table
• cell2table Convert cell array to table
• struct2table Convert structure array to table
• cell2mat Convert cell array to ordinary array of the underlying data type
• cell2struct Convert cell array to structure array
• mat2cell Convert array to cell array with potentially different sized cells
• num2cell Convert array to cell array with consistently sized cells
• struct2cell Convert structure to cell array