I have a .csv file with a list of numbers, what code can I use to check if an inputted number exists in that file.

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Tariq Hammoudeh
Tariq Hammoudeh 2021 年 12 月 2 日
コメント済み: Walter Roberson 2021 年 12 月 2 日
I have a .csv file that contains a list of account numbers. How can i check if an inputted number exists in that file. so for example, I write
AN= 256. What code can I use to check if '256' exists in the .csv file or not.

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Walter Roberson
Walter Roberson 2021 年 12 月 2 日
readtable(). ismember() the appropriate column of the table.
  2 件のコメント
Walter Roberson
Walter Roberson 2021 年 12 月 2 日
No, there is no MATLAB function that you can pass in a file name and a value and get back the response Yes the value exists in the file or No it does not exist in the file.
You need to read the data in and test the values once they are in memory.
help readtable
READTABLE Create a table by reading from a file. Use the READTABLE function to create a table by reading column-oriented data from a file. READTABLE automatically determines the file format from its extension as described below. T = READTABLE(FILENAME) creates a table by reading from a file, where FILENAME can be one of these: - For local files, FILENAME can be a full path that contains a filename and file extension. FILENAME can also be a relative path to the current folder, or to a folder on the MATLAB path. For example, to import a file on the MATLAB path: T = readtable("patients.xls"); - For files from an Internet URL or stored at a remote location, FILENAME must be a full path using a Uniform Resource Locator (URL). For example, to import a remote file from Amazon S3, specify the full URL for the file: T = readtable("s3://bucketname/path_to_file/my_table.xls"); For more information on accessing remote data, see "Work with Remote Data" in the documentation. T = READTABLE(FILENAME,"FileType",FILETYPE) specifies the file type, where FILETYPE is one of "text", "delimitedtext", "fixedwidth", "spreadsheet", "xml", "html", or "worddocument". T = READTABLE(FILENAME,OPTS) creates a table by reading from a file stored at FILENAME using the supplied ImportOptions OPTS. OPTS specifies variable names, selected variable names, variable types, and other information regarding the location of the data. For example, import a subset of the data in a file: opts = detectImportOptions("patients.xls"); opts.SelectedVariableNames = ["Systolic","Diastolic"]; T = readtable("patients.xls",opts) READTABLE reads data from different file types as follows: Text files (delimited and fixed-width): The following extensions are supported: .txt, .dat, .csv, .log, .text, .dlm Reading from a delimited text file creates one variable in T for each column in the file. Variable names can be taken from the first row of the file. By default, the variables created are either double, if the column is primarily numeric, or datetime, duration, or text etc. If data in a column cannot be converted to numeric, datetime or duration, the column is imported as text. Spreadsheet files: The following extensions are supported: .xls, .xlsx, .xlsb, .xlsm, .xltm, .xltx, .ods Reading from a spreadsheet file creates one variable in T for each column in the file. By default, the variables created are either double, datetime or text--depending on the type in the file. READTABLE converts both empty fields or cells and values which cannot be converted to the expected type to: - NaN (for a numeric or duration variable), - NaT (for a datetime variable), - Empty character vector ('') or missing string (for text variables). Word documents: The following extensions are supported: .docx Reading from a Word document file imports data from a table. Each column in the table creates one variable in T. Variable names can be taken from the first row of the table. By default, the variables created are either double, if the column is primarily numeric, or datetime, duration, or text etc. If data in a column cannot be converted to numeric, datetime or duration, the column is imported as text. The default data type for text import is string. HTML files: The following extensions are supported: .html, .xhtml, .htm Reading from an HTML file imports data from a <TABLE> element. Each column in the table creates one variable in T. Variable names can be taken from the first row of the table. By default, the variables created are either double, if the column is primarily numeric, or datetime, duration, or text etc. If data in a column cannot be converted to numeric, datetime or duration, the column is imported as text. The default data type for text import is string. XML files: The following extensions are supported: .xml Tabular structure present within an XML file: <table> ----------------------------- Table Node <row> --------------------------- Row Node <date>2019-07-11</date> ----- Variable Node <index>8191</index> <name>Lorem</name> </row> <row> <date>2020-01-04</date> <index>131071</index> <name>Ipsum</name> </row> </table> Reading from an XML file creates one row in T for each repeated node in the file that is detected under the table node. Variable names are taken from the names of the child nodes under the row nodes in the file. Name-Value Pairs for ALL file types: ------------------------------------ "FileType" - Specify the file as "text", "delimitedtext", "fixedwidth", "spreadsheet", "xml", "html", or "worddocument". "VariableNamingRule" - A character vector or a string scalar that specifies how the output variables are named. It can have either of the following values: 'modify' Modify variable names to make them valid MATLAB Identifiers. (default) 'preserve' Preserve original variable names allowing names with spaces and non-ASCII characters. "MissingRule" - Rules for interpreting missing or unavailable data: "fill" Replace missing data with the contents of the "FillValue" property. "error" Stop importing and display an error message showing the missing record and field. "omitrow" Omit rows that contain missing data. "omitvar" Omit variables that contain missing data. "ImportErrorRule" - Rules for interpreting nonconvertible or bad data: "fill" Replace the data where errors occur with the contents of the "FillValue" property. "error" Stop importing and display an error message showing the error-causing record and field. "omitrow" Omit rows where errors occur. "omitvar" Omit variables where errors occur. "ReadRowNames" - Whether or not to import the first variable as row names. Defaults to false. "TreatAsMissing" - Text which is used in a file to represent missing data, e.g. "NA". "TextType" - The type to use for text variables, specified as "char" or "string". "DatetimeType" - The type to use for date variables, specified as "datetime", "text", or "exceldatenum". Defaults to "datetime". Name-Value Pairs for TEXT and SPREADSHEET only: ----------------------------------------------- "Range" - The range to consider when detecting data. Specified using any of the following syntaxes: - Starting cell: A string or character vector containing a column letter and a row number, or a 2 element numeric vector indicating the starting row and column. - Rectangular range: A start and end cell separated by colon, e.g. "C2:N15", or a four element numeric vector containing start row, start column, end row, end column, e.g. [2 3 15 13]. - Row range: A string or character vector containing a starting row number and ending row number, separated by a colon. - Column range: A string or character vector containing a starting column letter and ending column letter, separated by a colon. - Starting row number: A numeric scalar indicating the first row where data is found. "NumHeaderLines" - The number of header lines in the file. "ExpectedNumVariables" - The expected number of variables. "ReadVariableNames" - Whether or not to expect variable names in the file. Defaults to true. Name-Value Pairs for TEXT, XML, HTML, and Word documents only: -------------------------------------------------------------- "DateLocale" - The locale used to interpret month and day names in datetime text. Must be a character vector or scalar string in the form xx_YY. See the documentation for DATETIME for more information. "DecimalSeparator" - Character used to separate the integer part of a number from the decimal part of the number. "ThousandsSeparator" - Character used to separate the thousands place digits. Name-Value Pairs for TEXT, XML, and HTML only: ---------------------------------------------- "Encoding" - The character encoding scheme associated with the file. Name-Value Pairs for TEXT and XML only: --------------------------------------- "DurationType" - The type to use for duration, specified as "duration" or "text". Defaults to "duration". "Whitespace" - Characters to treat as whitespace. "TrimNonNumeric" - Whether or not to remove nonnumeric characters from a numeric variable. Defaults to false. "HexType" - Set the output type of a hexadecimal variable. "BinaryType" - Set the output type of a binary variable. "CollectOutput" - Whether or not to concatenate consecutive output of the same MATLAB class into a single array. Defaults to false. Name-Value Pairs for TEXT, HTML, and Word documents only: --------------------------------------------------------- "RowNamesColumn" - The column where the row names are located. Name-Value Pairs for TEXT only: ------------------------------- "Delimiter" - Field delimiter characters in a delimited text file, specified as a character vector, string scalar, cell array of character vectors, or string array. "CommentStyle" - Style of comments, specified as a character vector, string scalar, cell array of character vectors, or string array. "LineEnding" - End-of-line characters, specified as a character vector, string scalar, cell array of character vectors, or string array. "ConsecutiveDelimitersRule" - Rule to apply to fields containing multiple consecutive delimiters: "split" Split consecutive delimiters into multiple fields. "join" Join the delimiters into one single delimiter. "error" Ignore consecutive delimiters during detection (treated as "split"), but the resulting read will error. "LeadingDelimitersRule" - Rule to apply to delimiters at the beginning of a line: "keep" Keep leading delimiters. "ignore" Ignore leading delimiters. "error" Ignore leading delimiters during detection, but the resulting read will error. "TrailingDelimiterRule" - Rule to apply to delimiters at the end of a line: "keep" Keep trailing delimiters. "ignore" Ignore trailing delimiters. "error" Ignore trailing delimiters during detection, but the resulting read will error. "VariableWidths" - Widths of the variables for a fixed width file. "EmptyLineRule" - Rule to apply to empty lines in the file: "skip" Skip empty lines. "read" Read empty lines. "error" Ignore empty lines during detection, but the resulting read will error. "VariableNamesLine" - The line where the variable names are located. "PartialFieldRule" - Rule to handle partial fields in the data: "keep" Keep the partial field data and convert the text to the appropriate data type. "fill" Replace missing data with the contents of the "FillValue" property. "omitrow" Omit rows that contain partial data. "omitvar" Omit variables that contain partial data. "wrap" Begin reading the next line of characters. "error" Ignore partial field data during detection, but the resulting read will error. "VariableUnitsLine" - The line where the variable units are located. "VariableDescriptionsLine" - The line where the variable descriptions are located. "ExtraColumnsRule" - Rule to apply to extra columns of data that appear after the expected variables: "addvars" Creates new variables to import extra columns. If there are N extra columns, then import new variables as "ExtraVar1", "ExtraVar2",..., "ExtraVarN". "ignore" Ignore the extra columns of data. "wrap" Wrap the extra columns of data to new records. "error" Display an error message and abort the import operation. Name-Value Pairs for SPREADSHEET only: -------------------------------------- "UseExcel" - Whether or not to read the spreadsheet file using Microsoft(R) Excel(R) on Windows(R): true - Opens an instance of Microsoft Excel to read the file on a Windows system with Excel installed. false - Does not open an instance of Microsoft Excel to read the file. This is the default setting. "Sheet" - The sheet from which to read the table. "DataRange" - Where the table data is located. "RowNamesRange" - Where the row names are located. "VariableNamesRange" - Where the variable names are located. "VariableUnitsRange" - Where the variable units are located. "VariableDescriptionsRange" - Where the variable descriptions are located. Name-Value Pairs for HTML and Word documents only: -------------------------------------------------- "TableIndex" - Integer selection which table to extract. "VariableNamesRow" - The row where the variable names are located. "VariableUnitsRow" - The row where the variable units are located. "VariableDescriptionsRow" - The row where the variable descriptions are located. "EmptyRowRule" - Rule to apply to empty lines in the file: "skip" Skip empty lines. "read" Read empty lines. "error" Ignore empty lines during detection, but the resulting read will error. "EmptyColumnRule" - Rule to apply to empty columns in the file: "skip" Skip empty columns. "read" Read empty columns. "error" Error on empty columns. Name-Value Pairs for HTML, Word documents, and XML only: -------------------------------------------------------- "TableSelector" - XPath expression that selects the table to extract. Name-Value Pairs for XML only: ------------------------------ "RowNodeName" - Node name which delineates rows of the output table. "RowSelector" - XPath expression that selects the XML Element nodes which delineate rows of the output table. "VariableNodeNames" - Node names which will be treated as variables of the output table. "VariableSelectors" - XPath expressions that select the XML Element nodes to be treated as variables of the output table. "TableNodeName" - Name of the node which contains table data. If multiple nodes have the same name, READTABLE uses the first node with that name. "VariableUnitsSelector" - XPath expression that selects the XML Element nodes containing the variable units. "VariableDescriptionsSelector" - XPath expression that selects the XML Element nodes containing the variable descriptions. "RowNamesSelector" - XPath expression that selects the XML Element nodes containing the row names. "RepeatedNodeRule" - Rule for managing repeated nodes in a given row of a table: "addcol" Add a column for each repeated node. "ignore" Ignore repeated nodes. "error" Ignore repeated nodes during detection, but the resulting read will error. "ImportAttributes" - Import XML node attributes as variables of the output table. Defaults to true. "AttributeSuffix" - Suffix to append to all output table variable names corresponding to attributes in the XML file. Defaults to "Attribute". "RegisteredNamespaces" - The namespace prefixes that are mapped to namespace URLs for use in selector expressions. Name-Value Pairs supported with Text and Spreadsheet Import Options OPTS: ------------------------------------------------------------------------- These have slightly different behavior when used with import options: T = readtable(FILENAME, OPTS, "Name1", Value1, "Name2", Value2, ...) "ReadVariableNames" true - Reads the variable names from the opts.VariableNamesRange or opts.VariableNamesLine location. false - Uses variable names from the import options. "ReadRowNames" true - Reads the row names from the opts.RowNamesRange or opts.RowNamesColumn location. false - Does not import row names. Text parameters: "DateLocale" - Override the locale used when importing dates. "Encoding" - Override the encoding defined in import options. Spreadsheet only parameters: "Sheet" - Override the sheet value in the import options. See also READTIMETABLE, READMATRIX, READCELL, WRITETABLE, TABLE, DETECTIMPORTOPTIONS, TEXTSCAN. Documentation for readtable doc readtable
help ismember
ISMEMBER True for set member. LIA = ISMEMBER(A,B) for arrays A and B returns an array of the same size as A containing true where the elements of A are in B and false otherwise. LIA = ISMEMBER(A,B,'rows') for matrices A and B with the same number of columns, returns a vector containing true where the rows of A are also rows of B and false otherwise. [LIA,LOCB] = ISMEMBER(A,B) also returns an array LOCB containing the lowest absolute index in B for each element in A which is a member of B and 0 if there is no such index. [LIA,LOCB] = ISMEMBER(A,B,'rows') also returns a vector LOCB containing the lowest absolute index in B for each row in A which is a member of B and 0 if there is no such index. The behavior of ISMEMBER has changed. This includes: - occurrence of indices in LOCB switched from highest to lowest - tighter restrictions on combinations of classes If this change in behavior has adversely affected your code, you may preserve the previous behavior with: [LIA,LOCB] = ISMEMBER(A,B,'legacy') [LIA,LOCB] = ISMEMBER(A,B,'rows','legacy') Examples: a = [9 9 8 8 7 7 7 6 6 6 5 5 4 4 2 1 1 1] b = [1 1 1 3 3 3 3 3 4 4 4 4 4 9 9 9] [lia1,locb1] = ismember(a,b) % returns lia1 = [1 1 0 0 0 0 0 0 0 0 0 0 1 1 0 1 1 1] locb1 = [14 14 0 0 0 0 0 0 0 0 0 0 9 9 0 1 1 1] [lia,locb] = ismember([1 NaN 2 3],[3 4 NaN 1]) % NaNs compare as not equal, so this returns lia = [1 0 0 1], locb = [4 0 0 1] Class support for inputs A and B, where A and B must be of the same class unless stated otherwise: - logical, char, all numeric classes (may combine with double arrays) - cell arrays of strings (may combine with char arrays) -- 'rows' option is not supported for cell arrays - objects with methods SORT (SORTROWS for the 'rows' option), EQ and NE -- including heterogeneous arrays derived from the same root class See also ISMEMBERTOL, INTERSECT, UNION, UNIQUE, UNIQUETOL, SETDIFF, SETXOR, SORT, SORTROWS. Documentation for ismember doc ismember Other functions named ismember categorical/ismember mtree/ismember cell/ismember nominal/ismember dataset/ismember sym/ismember datetime/ismember tabular/ismember duration/ismember tall/ismember gpuArray/ismember textanalytics.internal.wordlist/ismember

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