lookfor

Search for keyword in reference page text

Syntax

lookfor keyword

lookfor keyword -all

Description

lookfor keyword searches for the specified keyword in the summary line and function name of all the references pages in the MathWorks^® documentation as well as in the help text of third-party and user-authored MATLAB^® program files. For all references pages and help text in which a match occurs, lookfor displays a link to the help text for that page and the H1 line.

lookfor keyword -all searches the summary line, function name, and the Syntax, Description, Input Arguments, Output Arguments, and See Also sections of each reference page. For all references pages in which a match occurs, lookfor displays a link to the help text for that page and the individual lines in which a match occurs.

Examples

Search for Text in Summary Lines and Function Names

Search for the word inverse in the summary line and function name of all the references pages in the MathWorks documentation.

lookfor inverse

acos                           - Inverse cosine in radians
acosd                          - Inverse cosine in degrees
acosh                          - Inverse hyperbolic cosine
acot                           - Inverse cotangent in radians
acotd                          - Inverse cotangent in degrees
acoth                          - Inverse hyperbolic cotangent
acsc                           - Inverse cosecant in radians
acscd                          - Inverse cosecant in degrees
acsch                          - Inverse hyperbolic cosecant
...

Search for Text in All Reference Page Text

Search for the word inverse in the summary line, function name, and the Syntax, Description, Input Arguments, Output Arguments, and See Also sections of all the reference pages in the MathWorks documentation.

lookfor inverse -all

acos:
 acos - Inverse cosine in radians
    This MATLAB function returns the Inverse Cosine (cos-1) of the elements
        Inverse Cosine of Value
        Inverse Cosine of Vector of Complex Values
        Plot Inverse Cosine Function

acosd:
 acosd - Inverse cosine in degrees
    This MATLAB function returns the inverse cosine (cos-1) of the elements
        Inverse Cosine of 0

acosh:
 acosh - Inverse hyperbolic cosine
    This MATLAB function returns the inverse hyperbolic cosine of the
        Inverse Hyperbolic Cosine of Vector
        Plot the Inverse Hyperbolic Cosine Function
...

Input Arguments

keyword — Keyword to search for

character vector | string scalar

Keyword to search for, specified as a character vector or string scalar.

Alternative Functionality

As an alternative to the lookfor command, use the find features in the Current Folder browser. For example, you can look for all occurrences of a specified word in all the MATLAB program files in the current folder and its subfolders. For more information, see Find Files.

To search the documentation including third-party and custom documentation, use the docsearch function.

Version History

Introduced before R2006a

R2023a: Help text in third-party and user authored MATLAB program files searched

lookfor searches help text in third-party and user-authored MATLAB program files. In R2022b, lookfor does not search help text in third-party and user-authored MATLAB program files.

R2022b: Improved performance when searching

The lookfor function shows improved performance when searching for keywords.

For example, if you use the lookfor function to search for the keyword inverse in the summary line and function name of all the references pages in the MathWorks documentation, search results appear about 36x faster than in the previous release.

function timingTest
lookfor inverse
end

The approximate execution times are:

R2022a: 6.8885 s

R2022b: 0.1909 s

Similarly, if you use the lookfor function to search for the keyword inverse in the summary line, function name, and the Syntax, Description, Input Arguments, Output Arguments, and See Also sections of all the reference pages in the MathWorks documentation, search results appear about 5x faster than in the previous release.

function timingTest
lookfor inverse -all
end

The approximate execution times are:

R2022a: 9.5596 s

R2022b: 1.7926 s

The code was timed on a Windows 10, Intel^® Xeon^® CPU W-2133 @ 3.60 GHz test system using the timeit function.

timeit(@timingTest)

R2022b: Third-party and user authored help text no longer searched

lookfor no longer searches the help text in third-party and user authored MATLAB program files. In previous releases, lookfor searched all MATLAB program files on the path, including third-party and user authored program files.

To search the documentation including third-party and custom documentation, use the docsearch function instead. Alternatively you can use the find features in the Current Folder browser.