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author | Marti Bolivar <mbolivar@mit.edu> | 2010-12-03 20:18:00 -0500 |
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committer | Marti Bolivar <mbolivar@mit.edu> | 2010-12-03 20:18:00 -0500 |
commit | 5ceac644e90c929e77f05d357d1d35d45e673fac (patch) | |
tree | 18c76f6117942fa46391fbbd8bd24e2c759c4895 /docs/source/lang/randomseed.rst | |
parent | e5b1e44a8ae8c593456f4b4734f05c9065f6f07b (diff) | |
download | librambutan-5ceac644e90c929e77f05d357d1d35d45e673fac.tar.gz librambutan-5ceac644e90c929e77f05d357d1d35d45e673fac.zip |
cleaning up previous commits.
note that addition of new files under docs/source/lang/api and
docs/source/lang/cpp which were just copies of files in
docs/source/lang/ imply that change history is lost to git.
Diffstat (limited to 'docs/source/lang/randomseed.rst')
-rw-r--r-- | docs/source/lang/randomseed.rst | 60 |
1 files changed, 0 insertions, 60 deletions
diff --git a/docs/source/lang/randomseed.rst b/docs/source/lang/randomseed.rst deleted file mode 100644 index d0a15b7..0000000 --- a/docs/source/lang/randomseed.rst +++ /dev/null @@ -1,60 +0,0 @@ -.. highlight:: cpp - -.. _lang-randomseed: - -randomSeed() -============ - -``randomSeed()`` initializes the `pseudorandom number generator -<http://en.wikipedia.org/wiki/Pseudorandom_number_generator>`_, -causing it to start at an arbitrary point in its random sequence. -This sequence, while very long, and random, is always the same. - - -Library Documentation ---------------------- - -.. doxygenfunction:: randomSeed - -Discussion ----------- - -If it is important for a sequence of values generated by -:ref:`random() <lang-random>` to differ, on subsequent executions of a -sketch, use ``randomSeed()`` to initialize the random number generator -with a fairly random input, such as :ref:`analogRead() -<lang-analogread>` on an unconnected pin. - -Conversely, it can occasionally be useful to use pseudorandom -sequences that repeat exactly. This can be accomplished by calling -``randomSeed()`` with a fixed number, before starting the random -sequence. - -Example -------- - -The following sketch initializes the random seed based on an :ref:`ADC -<adc>` reading of pin 0. If this pin is unconnected, the Sketch -should print different values to the :ref:`serial monitor -<ide-serial-monitor>` each time it is run:: - - long randNumber; - - void setup() { - pinMode(0, INPUT_ANALOG); - randomSeed(analogRead(0)); - } - - void loop() { - randNumber = random(300); - SerialUSB.println(randNumber); - - delay(50); - } - -See Also --------- - -- :ref:`random() <lang-random>` - -.. include:: cc-attribution.txt |