Participation is voluntary. Pearson collects information requested in the survey questions and uses the information to evaluate, support, maintain and improve products, services or sites, develop new products and services, conduct educational research and for other purposes specified in the survey. Occasionally, we may sponsor a contest or drawing. Participation is optional.
Pearson collects name, contact information and other information specified on the entry form for the contest or drawing to conduct the contest or drawing.
Pearson may collect additional personal information from the winners of a contest or drawing in order to award the prize and for tax reporting purposes, as required by law. If you have elected to receive email newsletters or promotional mailings and special offers but want to unsubscribe, simply email information informit.
On rare occasions it is necessary to send out a strictly service related announcement. For instance, if our service is temporarily suspended for maintenance we might send users an email. Generally, users may not opt-out of these communications, though they can deactivate their account information. However, these communications are not promotional in nature.
We communicate with users on a regular basis to provide requested services and in regard to issues relating to their account we reply via email or phone in accordance with the users' wishes when a user submits their information through our Contact Us form.
Pearson automatically collects log data to help ensure the delivery, availability and security of this site. We use this information for support purposes and to monitor the health of the site, identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents and appropriately scale computing resources. Pearson may use third party web trend analytical services, including Google Analytics, to collect visitor information, such as IP addresses, browser types, referring pages, pages visited and time spent on a particular site.
While these analytical services collect and report information on an anonymous basis, they may use cookies to gather web trend information. The information gathered may enable Pearson but not the third party web trend services to link information with application and system log data. Pearson uses this information for system administration and to identify problems, improve service, detect unauthorized access and fraudulent activity, prevent and respond to security incidents, appropriately scale computing resources and otherwise support and deliver this site and its services.
This site uses cookies and similar technologies to personalize content, measure traffic patterns, control security, track use and access of information on this site, and provide interest-based messages and advertising. Users can manage and block the use of cookies through their browser. Disabling or blocking certain cookies may limit the functionality of this site. Pearson uses appropriate physical, administrative and technical security measures to protect personal information from unauthorized access, use and disclosure.
Pearson may provide personal information to a third party service provider on a restricted basis to provide marketing solely on behalf of Pearson or an affiliate or customer for whom Pearson is a service provider.
Marketing preferences may be changed at any time. If a user's personally identifiable information changes such as your postal address or email address , we provide a way to correct or update that user's personal data provided to us.
This can be done on the Account page. If a user no longer desires our service and desires to delete his or her account, please contact us at customer-service informit. Users can always make an informed choice as to whether they should proceed with certain services offered by InformIT. If you choose to remove yourself from our mailing list s simply visit the following page and uncheck any communication you no longer want to receive: www. While Pearson does not sell personal information, as defined in Nevada law, Nevada residents may email a request for no sale of their personal information to NevadaDesignatedRequest pearson.
With the Method option, the stream is opened using the given input stream method. This overrides the default way that OpenRead resolves file names. OpenRead [ File [ " file " ] ] is also supported. Basic Examples 1 Open a file:. Scope 1 Open the file specified by the File object:. History Introduced in 1. This closes it:. This reads the first byte from the file, returning it as an integer:.
This reads the second 8 bits in the file as a character:. But if you give a file name, they automatically open the specified file as a stream. To create a stream directly you can use OpenRead or OpenWrite.
In using the Wolfram Language you are normally completely insulated from the raw representation of data inside your computer. But with BinaryRead and BinaryWrite this is no longer so. This reads the integer back, but assumes an opposite byte ordering:. BinaryReadList [ " file " ] read all the bytes in a file. This reads back the bytes in the number:. BinaryRead and BinaryWrite allow complete flexibility in reading and writing raw binary data.
But in many practical applications one instead wants to work only with particular predefined formats. You can do this using Import and Export. In addition to many complex formats, Import and Export support files containing sequences of identical data elements, of the same types as in BinaryRead and BinaryWrite.
They also support the "Bit" format, consisting of individual binary bits, represented as 0 or 1. The Wolfram Language allows you to convert mathematical expressions into C and Fortran expressions. CForm [ expr ] write out expr so it can be used in a C program. Wolfram Language output for programming languages. Here is an expression, written out in standard Wolfram Language form:.
Here is the expression in Fortran form:. Here is the same expression in C form. Macros for objects like Power are defined in the C header file mdefs. If you want to generate a C version of an entire expression you can do this with Export to C. One of the common motivations for converting Wolfram Language expressions into C or Fortran is to try to make them faster to evaluate numerically. But the single most important reason that C and Fortran can potentially be more efficient than the Wolfram Language is that in these languages the user always specifies up front what type each variable will be — integer, real number, array, and so on.
The Wolfram Language function Compile makes such assumptions within the Wolfram Language, and generates highly efficient internal code. This can be made to run even faster by setting the CompilationTarget to "C". Compile [ x , expr ] compile an expression into efficient internal code. A Wolfram Language script is simply a file containing Wolfram Language commands that you would normally evaluate sequentially in a Wolfram Language session.
Writing a script is useful if the commands need to be repeated many times. Collecting these commands together ensures that they are evaluated in a particular sequence with no command omitted. This is important if you run complex and long calculations.
When you use the Wolfram Language interactively, the commands contained in the script file can be evaluated using Get. This function can also be used programmatically in your code or other. Get [ " file " ] read in a file and evaluate commands in it. Reading commands from a script file. There is no requirement concerning the structure of the script file. Any sequence of Wolfram Language commands given in the file will be read and evaluated sequentially.
If your code is more complex than a plain list of commands, you may want to consider writing a more structured package, as described in "Setting Up Wolfram Language Packages".
The Wolfram Language script is more useful when there is no need for an interactive session; that is, when your script encapsulates a single calculation that needs to be performed — for example, if your calculation involves heavy computational tasks, such as linear algebra, optimization, numerical integration, or solution of differential equations, and when you do not use typesetting, dynamic interactivity, or notebooks.
Scripts may be stored either in normal. The contents of both files are the same: a series of Wolfram Language expressions, with an optional "shebang" line at the start for use on Unix-like operating systems see Unix Script Executables. The only difference between the file types is their double-click behavior. Double-clicking a package file will open the file in the notebook package editor, while double-clicking a script file will execute it when supported by the operating system.
This is particularly advantageous on Windows, where it is not possible to associate a program with a particular file, only a file extension. The script file can be used when invoking the Wolfram Language kernel from the command line, using the following typical locations for the kernel executable.
Running the script file on Windows. Running the script file on macOS. The -script command line option specifies that the Wolfram Language kernel is to be run in a special script, or batch, mode. In this mode, the kernel reads the specified file and sequentially evaluates its commands. The kernel turns off the default linewrapping by setting the PageWidth option of the output functions to Infinity and prints no In [ ] and Out [ ] labels. When run in this mode, the standard input and output channels , , and are not redirected, and numbers are formatted in InputForm.
Running wolfram with the -script option is equivalent to reading the file using the Get command, with a single difference: after the last command in the file is evaluated, the kernel terminates. This behavior may have an effect on the Wolfram Symbolic Transfer Protocol WSTP connections or external processes that were created by running the script.
Scripts can also be run using the WolframScript interpreter as follows. The -file flag is optional. Running the script using WolframScript. WolframScript will find the best local kernel it can to run the script. If it fails to find any local kernels, it will connect to the cloud and run the script there. The program accepts various flags in order to control which local or cloud kernel is used for evaluation. It also sets Script Parameters, which allow the script to change its behavior based on how it was launched or what input in receives.
Another advantage of using WolframScript is that input and output are fully buffered, allowing various transforms to be applied to them. All of these additional options are described along with examples on the WolframScript page. On Mac, it is necessary to run the "Extras" installer bundled with the Wolfram System in order to obtain WolframScript.
These installers will place wolframscript on the PATH by default. Unix-like operating systems — as well as Unix environments for Windows such as cygwin and MinGW — allow writing scripts that can be made executable and run as regular executable programs. This is done by putting an "interpreter" line at the beginning of the file. The same can be done with the script containing Wolfram Language commands. The "interpreter" line consists of two characters,!
The env program will find wolframscript on the PATH and then launch it correctly. To make the script executable, you need to set executable permissions.
After that, the script can be run simply by typing its name at a shell prompt. Make the script executable and run it. The interpreter line may additionally contain other parameters for the interpreter.
Possible parameters are specified on the WolframScript page. Interpreter line using additional parameters. The Wolfram Language script does not need to have the. An executable script is a full-featured program equivalent to any other program in a Unix operating system, so it can be used in other scripts, in pipes, subject to job control, etc. Each Wolfram Language script launches its own copy of the WolframKernel , which does not share variables or definitions.
Note that running Wolfram Language scripts concurrently may be affected by the licensing restriction on how many kernels you may run simultaneously. Executable script files can be transparently read and evaluated in an interactive Wolfram Language session. The Get command will normally ignore the first line of the script if it starts with the! It is possible to avoid the use of the env program, but then the path to wolframscript must be an absolute path.
The operating system mechanism used to launch the script does not use PATH or other means to find the file. Moreover, the path to the interpreter may not contain spaces. Standalone scripts can also be used on Windows. Unlike Unix-like operating systems, these scripts must have the extension. They can be launched from Windows Explorer by double-clicking them, and from Command Prompt by simply typing in their name. The Unix interpreter line, if present, is ignored by this mechanism.
Launching a script from the command prompt, equivalent to the double-click action. In Command Prompt, additional arguments can be passed after the file name. These arguments are not seen by WolframScript itself, but are instead passed to the script as parameters, as explained in the next section.
Launching a script from the command prompt with two additional arguments. When running a Wolfram Language script, you may often want to modify the behavior of the script by specifying parameters on the command line. Variables that give information about how the script is run. Example of a script file, file. Run the script and specify the number of samples in a Unix environment. Run the script and specify the number of samples on Windows. Notice that this completely hides the path to the interpreter or any arguments passed to it on the!
Give Feedback Top. Searching and Reading Strings. Naming and Finding Files. Generating C and Fortran Expressions. Manipulating Files and Directories. Wolfram Language Scripts. Reading Textual Data. FilePrint [ " file " ]. Save [ " file " , symbol ]. Encode [ " source " , " dest " ].
OpenWrite [ ]. RunThrough [ " command " , expr ]. SystemOpen [ " target " ]. InputStream [ " name " , n ]. OutputStream [ " name " , n ]. OpenWrite [ " file " ]. OpenAppend [ " file " ]. OpenWrite [ "! Write [ stream , expr 1 , expr 2 , … ]. WriteString [ stream , str 1 , str 2 , … ].
Close [ stream ]. Options [ stream ]. Directory [ ]. SetDirectory [ " dir " ]. ResetDirectory [ ]. ParentDirectory [ ]. FindFile [ " name " ]. FileExistsQ [ " name " ]. FileNames [ ]. FileNames [ " form " ]. FileNames [ forms , dirs , n ].
FileNames [ forms , dirs , Infinity ]. DirectoryName [ " file " ]. ParentDirectory [ " directory " ]. FileNameSplit [ " name " ]. FileNameTake [ " name " , … ]. FileNameDrop [ " name " , … ].
FileNameDepth [ " name " ]. FileBaseName [ " name " ]. FileExtension [ " name " ]. RenameFile [ " file 1 " , " file 2 " ]. DeleteFile [ " file " ]. FileByteCount [ " file " ]. FileDate [ " file " ]. Once established, a stream maintains its orientation until it is closed by a call to fclose or freopen. Skip to main content. This browser is no longer supported. Download Microsoft Edge More info. Contents Exit focus mode. Is this page helpful?
Please rate your experience Yes No.
0コメント