'\n'怎么放?放到哪才有换行作用?谢谢 | 您所在的位置:网站首页 › java换行输出语句格式怎么设置 › '\n'怎么放?放到哪才有换行作用?谢谢 |
headerlines表示开头跳过几行(有的文件开头有说明文字)delimiter 设置分隔符,用来隔开多个数据,whitespace表示把这个字符作为空格来处理 区别是分隔符更严格,只要读到这个字符,当前的这个数据就截止了,空格则不一定,具体情况自己试验一下了 help里说的很详细,懂英文的话自己看下textread Read data from text file; write to multiple outputs Note textread is not recommended. Use textscan to read data from a text file. Graphical Interface As an alternative to textread, use the Import Wizard. To activate the Import Wizard, select Import Data from the File menu.Syntax [A,B,C,...] = textread('filename','format')[A,B,C,...] = textread('filename','format',N)[...] = textread(...,'param','value',...)Description [A,B,C,...] = textread('filename','format') reads data from the file 'filename' into the variables A,B,C, and so on, using the specified format, until the entire file is read. The filename and format inputs are strings, each enclosed in single quotes. textread is useful for reading text files with a known format. textread handles both fixed and free format files. Note When reading large text files, reading from a specific point in a file, or reading file data into a cell array rather than multiple outputs, you might prefer to use the textscan function. textread matches and converts groups of characters from the input. Each input field is defined as a string of non-white-space characters that extends to the next white-space or delimiter character, or to the maximum field width. Repeated delimiter characters are significant, while repeated white-space characters are treated as one. The format string determines the number and types of return arguments. The number of return arguments is the number of items in the format string. The format string supports a subset of the conversion specifiers and conventions of the C language fscanf routine. Values for the format string are listed in the table below. White-space characters in the format string are ignored. format Action Output Literals (ordinary characters) Ignore the matching characters. For example, in a file that has Dept followed by a number (for department number), to skip the Dept and read only the number, use 'Dept' in the format string. None%d Read a signed integer value. Double array%u Read an integer value. Double array%f Read a floating-point value. Double array%s Read a white-space or delimiter-separated string. Cell array of strings%q Read a double quoted string, ignoring the quotes. Cell array of strings%c Read characters, including white space. Character array%[...] Read the longest string containing characters specified in the brackets. Cell array of strings%[^...] Read the longest nonempty string containing characters that are not specified in the brackets. Cell array of strings%*...instead of % Ignore the matching characters specified by *. No output%w...instead of % Read field width specified by w. The %f format supports %w.pf, where w is the field width and p is the precision. [A,B,C,...] = textread('filename','format',N) reads the data, reusing the format string N times, where N is an integer greater than zero. If N is smaller than zero, textread reads the entire file. [...] = textread(...,'param','value',...) customizes textread using param/value pairs, as listed in the table below. param value Actionbufsize Positive integer Specifies the maximum string length, in bytes. Default is 4095.commentstyle matlab Ignores characters after %.commentstyle shell Ignores characters after #.commentstyle c Ignores characters between /* and */.commentstyle c++ Ignores characters after //.delimiter One or more characters Act as delimiters between elements. Default is none.emptyvalue Scalar double Value given to empty cells when reading delimited files. Default is 0.endofline Single character or '\r\n' Character that denotes the end of a line. Default is determined from fileexpchars Exponent characters Default is eEdD.headerlines Positive integer Ignores the specified number of lines at the beginning of the file.whitespace Any from the list below: Treats vector of characters as white space. Default is ' \b\t'.' '\b\n\r\t SpaceBackspaceNewlineCarriage returnHorizontal tab Note When textread reads a consecutive series of whitespace values, it treats them as one white space. When it reads a consecutive series of delimiter values, it treats each as a separate delimiter. Remarks If you want to preserve leading and trailing spaces in a string, use the whitespace parameter as shown here: textread('myfile.txt', '%s', 'whitespace', '')ans = ' An example of preserving spaces ' ExamplesExample 1 — Read All Fields in Free Format File Using % The first line of mydata.dat is Sally Level1 12.34 45 Yes Read the first line of the file as a free format file using the % format. [names, types, x, y, answer] = textread('mydata.dat', ...'%s %s %f %d %s', 1) returns names = 'Sally'types = 'Level1'x =12.34000000000000y =45answer = 'Yes' Example 2 — Read as Fixed Format File, Ignoring the Floating Point Value The first line of mydata.dat is Sally Level1 12.34 45 Yes Read the first line of the file as a fixed format file, ignoring the floating-point value. [names, types, y, answer] = textread('mydata.dat', ...'%9c %5s %*f %2d %3s', 1) returns names =Sally types = 'Level1'y =45answer = 'Yes' %*f in the format string causes textread to ignore the floating point value, in this case, 12.34.Example 3 — Read Using Literal to Ignore Matching Characters The first line of mydata.dat is Sally Type1 12.34 45 Yes Read the first line of the file, ignoring the characters Type in the second field. [names, typenum, x, y, answer] = textread('mydata.dat', ...'%s Type%d %f %d %s', 1) returns names = 'Sally'typenum =1x =12.34000000000000y =45answer = 'Yes' Type%d in the format string causes the characters Type in the second field to be ignored, while the rest of the second field is read as a signed integer, in this case, 1.Example 4 — Specify Value to Fill Empty Cells For files with empty cells, use the emptyvalue parameter. Suppose the file data.csv contains: 1,2,3,4,,67,8,9,,11,12 Read the file using NaN to fill any empty cells: data = textread('data.csv', '', 'delimiter', ',', ... 'emptyvalue', NaN); Example 5 — Read M-File into a Cell Array of Strings Read the file fft.m into cell array of strings. file = textread('fft.m', '%s', 'delimiter', '\n', ...'whitespace', '');
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