A formatting operator starts with a percent sign, %, and ends with a conversion character. Convert string arrays to character arrays, leaving other. Variable names for the output dataset array, specified as the commaseparated pair consisting of varnames and a string array or cell array of character vectors. If you specify a conversion that does not fit the data, such as a text conversion for a numeric value, matlab overrides the specified conversion, and uses %e. Convert the string array and return the other arrays unaltered. Use string variable as variable name physics forums.
Turn them into real indices and your problem instantly goes away. Sep 03, 2011 convert a variable parameter to string. It calls the eval function which can have unintended consequences. I am trying to use a generated string to control in which variable an answer is recorded. Convert string to cell array matlab answers matlab central. Is there a way to do this without having to store the name. Many beginners in programming struggle with the problem of hiding indices in the names of variables, because they do not have enough experiences with the efficient using of arrays. I think the only way to really do it is from the answer from the question you cited. If the input array has no name, then cell2table creates variable names of the form var1. See example 6, below the variable name returned by genvarname is not. Aug 31, 20 i think the only way to really do it is from the answer from the question you cited. You clicked a link that corresponds to this matlab command.
Is it possible to transform a string to a variable code name in matlab. String arrays provide a set of functions for working with text as data. Convert char to string matlab answers matlab central. X str2doublestr converts the text in str to double precision values. Starting in r2017a, you can create strings using double quotes, such as str greetings friend. If a is a string array, then char converts the string array to a character array. What should i do to make the second command return data. Matlab considers all variables as arrays, and strings are considered as character arrays. How to convert a string to int matlab answers matlab. You can also use the double function for string arrays. Convert string to variable matlab answers matlab central. To avoid these issues, use str2double as an alternative, you can convert strings to doubleprecision values using the.
The maximum length of a variable name is the value that the namelengthmax command returns you cannot define variables with the same names as matlab keywords, such as if or end. I never had tried it without explicitly converting the string by cellstr at first. Solving problems through better code design is always preferred to writing slow, buggy, hack code accessing variable names. Convert cell to variable name array matlab answers matlab. It treats string arrays, character vectors, and cell arrays of character vectors consistently. Oct 29, 2015 the problem is that i have several variables in the for loop whose definition and value depend on the year suffix, that is they are constructed by combaining a letter k,g, and so on with the year number, so that they become k2006, g2006 and so on in the first iteration, k2007, g2007 and so on in the second iteration, and i have to consider also possible more years. The names must be valid matlab identifiers, and must be unique.
You must provide a variable name for each variable in ds. X str2numchr converts a character array or string scalar to a numeric matrix. How can i get the name of a matlab variable as a string. Its convenient to read and simultaneously name the variables per a filename. Field names that you reference with expressions are called dynamic fieldnames, or sometimes dynamic field names. Convert matrix to characters matlab mat2str mathworks. The maximum length of a variable name is the value that the namelengthmax command returns. How to convert the name of a table or cell array to string matlab. I have generated the variable name in which i intend to record the data with.
I have a variable vector defined at the beginning of my code, say a1. If you use this syntax to produce chr, then a evalchr also reproduces the data type of the original matrix. Jan 29, 2018 i would like to convert the name of my matlab variable to a string so that, for example, i can plot a variable and then use the name of the variable as a title for the plot. The problem is that you are hiding pesudoindices in variable names. They appear in the simulink editor as strn for example, string with maximum length of n characters or string for strings without maximum length dynamic strings. This matlab function constructs a string or character vector varname that is similar to or the same as the str input, and can be used as a valid variable name. Data type of the converted variables, specified as a character vector, string scalar, or function handle. Matlab will execute the above statement and return the following result. I would like to convert the name of my matlab variable to a string so that, for example, i can plot a variable and then use the name of the variable as a title for the plot. Apart from the string concatenation functions see concatenating strings which cast numerical data to the corresponding ascii characters, there are several functions that format numerical data as strings. Text to convert to a function handle, specified as a function name or a character vector or string scalar representation of an anonymous function. The exclusions input can be a string, a string array, a character array, a cell array of character vectors. Apr 25, 2012 convert cell to string, or assign variable.
A valid matlab variable name is a character string of letters, digits, and underscores, such that the first character is a letter, and the length of the string is less than or equal to the value returned by the namelengthmax function. Construct function handle from character vector matlab str2func. How to convert string into filename then use load comment. Construct valid variable name from string matlab genvarname. Workspace variable name, returned as a character vector.
Interchange variable names and strings matlab answers. T cell2tablec converts the contents of an mbyn cell array, c, to an mbyn table, t. Convert cell array to string matlab answers matlab central. Specify the function who in exclusions to create a variable name that will be unique in the current matlab. How to convert string to variable name which will be passed into plot function.
Learn more about strings, variables, conversion, workspace, sprintf, str2, eval. If datatype is a function handle, then the function must accept one input argument and convert it to another data type. I would like to be able to get the name of the variable i am plotting, extract it in a string and use it to title my plot. Learn more about data, strings, number, convert, workspace. B casta,newclass converts a to the data type class newclass, where newclass is the name of a builtin data type compatible with a. If a variable contains an empty array, disp returns without displaying anything. Id like to do this so that i can run functions on the variables and have the plot titles include the variable name. Convert variable to different data type matlab cast. In addition, str2num uses the eval function, which can cause unintended side effects when the input includes a function name. You can get the string of hex digits into your code by hard coding it, by accepting it as an input argument to your function, or even using the input function.
Convert cell to string, or assign variable matlab answers. I would like to convert the name of my matlab variable to a string so that, for example, i can plot a variable and then use the name of the variable as a title for. Headings time, speed, distance now, i want to have a variable that uses the text inside headings as its name with 1,2,3,4 inside. To enable your existing code to accept string arrays as input, add a call to convertstringstochars at the beginning of your code. The cast function truncates any values in a that are outside the range of newclass to the nearest endpoint. How to convert a string to int matlab answers matlab central. You can use this syntax with any of the arguments from the previous syntaxes. Convert integers to characters matlab int2str mathworks.
For example, create a field name from the current date. If myfunc accepts a variable number of input arguments. How to convert string to variable name which will be passed. If you use genvarname to generate a field name for a structure, matlab does create a variable for the structure and field in the matlab workspace. Jul 08, 2011 each of those strings that are variable names are variables whos values are arrays and id like to concatenate whatever variables do exist. Matlab input string as variable name or other ways. Currently it is not clear, if your data are a double vector, a cell vector or any equivalent data also. Valid variable names can include letters, digits, and underscores.
Format of the output fields, specified using formatting operators. Convert running matlab session to shared session matlab. You may receive emails, depending on your notification preferences. Potential variable name, specified as a character vector, or string. If used on unsupported data types, strcmp always returns 0. Starting in r2016b, you can convert numeric arrays to string arrays using the string function. In that case, it is a handle to a function that converts or otherwise modifies the variables specified by vars. If you apply a text conversion either %c or %s to integer values, matlab converts values that correspond to valid character codes to. If str is a cell array of character vectors or a string array, then x is a numeric array that is. Jul 05, 2012 hi, how to save a file with the characters of a string as the file name. If str2double cannot convert text to a number, then it returns a nan value while the str2num function can also convert text to numbers, it is not recommended.
If the str input contains any whitespace characters, genvarname removes then and capitalizes the next alphabetic character in str. If there is already a shared matlab session on your local machine that has the specified name, then matlab. How to convert a number to string in matlab youtube. B convertcharstostrings a converts a to a string array if a is a character array or a cell array of character vectors. How can i convert a string which contains a variable name into a. How to convert a variable name to a string in matlab quora. Using strings as variable names in a for loop matlab. How do i convert a string to a variable name and vice versa i want to read in a string, and use it as a variable name, such as when i load a. For example, you can specify the display format of t using the format namevalue pair argument for best performance when creating datetime values from text, specify either format or inputformat and its corresponding. Any string that exceeds namelengthmax is truncated in the varname output.
To convert text to numeric values, use the str2double function. I have a variable called headings, inside it is a bunch of text time, speed, distance. Please post the input data such that we can know the class and the size. For example, an input argument has no name if it is a number, an expression, or an indexing expression instead of a variable. When the input argument is a string array, the double function treats each element as the representation of a floatingpoint value. If str2num cannot parse the input as numeric values, then it returns an empty matrix.
May 12, 2011 i have a question on how to make use of string variable specifying a filename on the load command to load the data into the workspace. It might not make sense to define a string with a variable and try to convert it to the variable itself but it will be helpful in my code. Matlab is case sensitive, so a and a are not the same variable. Is there a way that i can convert these variable names into strings. Dec 20, 2012 im still confused about string, cell string, because it looks like this joins elements of incompatible types. How can i get a variable name to include a specified string. If a string array represents numbers, then you can convert it to a numeric array using the double function. A valid variable name starts with a letter, followed by letters, digits, or underscores. For example, the string function converts an input argument to a string array. Thorsten just needed some data to show how to use hex2dec.
Let us use the whos command to check the variable created above. If str is a character vector or string scalar, then x is a numeric scalar. Learn more about matlab, eval, dynamic variable names matlab. Determine if input is valid variable name matlab isvarname. This matlab function treats n as a matrix of integers and converts it to a character array that represents the integers. The input can include spaces, commas, and semicolons to indicate separate elements. This may seem like a waste of time as it would be quicker to type ab1 each type rather than evaluating text, but i will be copying the same code multiple times and i want to only change text each time rather than the names of all the variables. So say i have variables with variable names like swcf and lwcf. For example, if you have defined a function myfunc that accepts three input arguments, process all three inputs using convertstringstochars.
Convert character array or string to numeric array matlab. For instance i read to a temp var then use the illadvised exec capability to assign this to a variable specific to the file i read in. Oct 17, 2008 how do you a string in a variable as a name for another variable. I want to use string variables a as variable name to outputb. You cannot define variables with the same names as matlab keywords. Each of those strings that are variable names are variables whos values are arrays and id like to concatenate whatever variables do exist. T2 convertvarst1,vars,datatype converts the specified variables to the specified data type.
Then you do not have to make any other changes to code you had written to work with string arrays. Otherwise it returns logical 0 false a valid variable name begins with a letter and contains not more than namelengthmax characters. Jan 03, 20 the main intent is to write a generic function with which i can assign valueswrites to files etc. I would like to ask the user to input the name of a variable and then use that string as a new variable name. The strcmp function is intended for comparison of text. Each column of c provides the data contained in a variable of t to create variable names in the output table, cell2table appends column numbers to the input array name. Field names that you reference with expressions are called dynamic fieldnames, or sometimes dynamic field names for example, create a field name from the current date. If the input argument has no name, the inputname function returns an empty character array. For caseinsensitive text comparison, use strcmpi instead of strcmp although strcmp shares a name with a c function, it does not follow the c language convention of returning 0 when the text inputs match with string arrays, you can use relational operators. Is there a way to do this without having to store the name of the variable along with the data. While you can specify datatype as the name of a data type, you also can specify it as a function handle. When working with your own code, you can use convertcharstostrings to make your code accept character arrays. If str is a string array or cell array of character vectors, genvarname returns a string array or cell array of character. Assigning input string as variable name matlab answers.
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