MapReduce
mapreduce
es una técnica de programación adecuada para analizar conjuntos de datos de gran tamaño que, de lo contrario, no cabrían en la memoria de su equipo. Utilizando datastore
para procesar los datos en pequeñas partes, la técnica consta de una fase de asignación, donde se da formato a los datos o se realiza un cálculo precursor, y una fase de reducción, donde se agregan todos los resultados provenientes de la fase de asignación. Para obtener más información, consulte Getting Started with MapReduce.
Para obtener información sobre cómo usar otros productos con mapreduce
, consulte Speed Up and Deploy MapReduce Using Other Products.
Funciones
Objetos
KeyValueStore | Store key-value pairs for use with mapreduce |
ValueIterator | An iterator over intermediate values for use with mapreduce |
Temas
- Getting Started with MapReduce
Learn about the MapReduce programming technique and run an example calculation.
- Write a Map Function
Create a map function for use in a
mapreduce
algorithm. - Write a Reduce Function
Create a reduce function for use in a
mapreduce
algorithm. - Build Effective Algorithms with MapReduce
Summary of
mapreduce
example files. - Speed Up and Deploy MapReduce Using Other Products
Capabilities of other products to speed up and share
mapreduce
algorithms. - Find Maximum Value with MapReduce
This example shows how to find the maximum value of a single variable in a data set using
mapreduce
. - Compute Mean Value with MapReduce
This example shows how to compute the mean of a single variable in a data set using
mapreduce
. - Create Histograms Using MapReduce
This example shows how to visualize patterns in a large data set without having to load all of the observations into memory simultaneously.
- Compute Mean by Group Using MapReduce
This example shows how to compute the mean by group in a data set using
mapreduce
. - Simple Data Subsetting Using MapReduce
This example shows how to extract a subset of a large data set.
- Using MapReduce to Compute Covariance and Related Quantities
This example shows how to compute the mean and covariance for several variables in a large data set using
mapreduce
. - Compute Summary Statistics by Group Using MapReduce
This example shows how to compute summary statistics organized by group using
mapreduce
. - Using MapReduce to Fit a Logistic Regression Model
This example shows how to use
mapreduce
to carry out simple logistic regression using a single predictor. - Tall Skinny QR (TSQR) Matrix Factorization Using MapReduce
This example shows how to compute a tall skinny QR (TSQR) factorization using
mapreduce
. - Compute Maximum Average HSV of Images with MapReduce
This example shows how to use
ImageDatastore
andmapreduce
to find images with maximum hue, saturation and brightness values in an image collection.
Solución de problemas
This example shows how to debug your mapreduce
algorithms
in MATLAB® using a simple example file, MaxMapReduceExample.m
.
Debugging enables you to follow the movement of data between the different
phases of mapreduce
execution and inspect the
state of all intermediate variables.