www.gusucode.com > datafun 工具箱matlab源码程序 > datafun/ismissing.m
function IA = ismissing(A,indicators) %ISMISSING Find missing entries % First argument must be numeric, datetime, duration, calendarDuration, % string, categorical, character array, cell array of character vectors, % a table, or a timetable. % Standard missing data is defined as: % NaN - for double and single floating-point arrays % NaN - for duration and calendarDuration arrays % NaT - for datetime arrays % <missing> - for string arrays % <undefined> - for categorical arrays % blank character [' '] - for character arrays % empty character {''} - for cell arrays of character vectors % % IA = ISMISSING(A) returns a logical array IA indicating the standard % missing values found in A. IA has the same size as A. % % IA = ISMISSING(A,INDICATORS) uses the entries in INDICATORS to specify % which entries of A are missing. Use INDICATORS to find non-standard % missing values. If A is an array, INDICATORS must be a vector. If A is % a table, INDICATORS can also be a cell with entries of different types. % % Double entries in INDICATORS match double, single, integer, and logical % entries in A. Single, integer, and logical entries in INDICATORS match % single, integer, and logical entries in A, respectively. % % String, character, duration, and datetime entries in INDICATORS match % string, character, duration, and datetime entries in A, respectively. % % String and character INDICATORS also match categorical entries in A. % % You can include NaN, NaT, the missing string, the empty character '', % or '<undefined>' in INDICATORS to also find standard missing values. % % Integers cannot store NaN, therefore you must include a special unused % integer value in INDICATORS to find missing integer data in A. % % Examples: % % % IA is TRUE for the entries of A that are NaN % A = [NaN 1 2 NaN NaN 3] % IA = ismissing(A) % % % IA is TRUE for the entries of A that are missing strings % A = string({'Mercury','Gemini'}); A(5) = 'Apollo' % IA = ismissing(A) % % % Find both standard (NaN and <undefined>) and non-standard % % (-99 and '--') missing entries in table T. % % Use the '' indicator to find the <undefined> categorical entry. % temperature = [21.1 21.5 NaN 23.1 25.7 24.1 25.3 NaN 24.1 25.5]'; % windSpeed = [12.9 13.3 12.1 13.5 10.9 -99 -99 12.2 10.8 17.1]'; % windDirection = categorical({'W' 'SW' 'SW' '' 'SW' 'S' ... % 'S' 'SW' 'SW' 'SW'})'; % conditions = {'PTCLDY' '--' '--' 'PTCLDY' 'FAIR' 'CLEAR' ... % 'CLEAR' 'FAIR' 'PTCLDY' 'MOSUNNY'}'; % T = table(temperature,windSpeed,windDirection,conditions) % IT = ismissing(T,{NaN -99 '' '--'}) % % See also STANDARDIZEMISSING, RMMISSING, FILLMISSING, ISNAN, ISNAT % Copyright 2012-2016 The MathWorks, Inc. if nargin <= 1 IA = matlab.internal.math.ismissingKernel(A); else IA = matlab.internal.math.ismissingKernel(A,indicators,false); end