Questions tagged [pyspark]
The Spark Python API (PySpark) exposes the apache-spark programming model to Python.
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(Py)Spark infrastructure for use in Java/C# website
Lets say I have experience creating ML models in Python, and have decided on training my models on Spark using Pyspark. This will form part of an ML infrastructure for a website with a Java or C# ...
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19 views
Running LSTM model on a big data sample using pyspark
I was wondering how does one run an LSTM model on a big dataframe in pyspark. Ideally, one wants to run the model parallelly on different nodes of a spark cluster. But how does one do that?
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4 views
Unseing label in PySpark MultilayerPerceptronClassifier
I'm trying to perform classification with a MLP in PySpark:
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2answers
21 views
customer segmentation with unbalanced data
I am trying to do a customer segmentation on my transactional data and I am struggling a little bit on the best approach. Since it is an unsupervised model I can throw it to any algorithm and get some ...
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1answer
12 views
Which ML method for multiclass (non-binary) text classification should I choose (from SparkML)?
I am working on a quite big dataset that will be processed on the cluster, so this is why I am using PySpark for that purpose.
The presentable records of this dataset have a such structure:
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15 views
How to store subset of columns from a csv file?
I need to create a table in hive (or Impala) by reading from a csv file (named file.csv), ...
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22 views
Jupyter notebook pyspark error in %manage_spark
The environment is Jupyterhub on Centos using Pyspark kernel. When trying to run the below commands in JupyterLab I get errors. But the same commands work fine if I revert to regular Jupyter notebook ...
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11 views
Setting up Zeppelin to work with a Spark Cluster
I have made a spark cluster containing 2 workers and 1 master. I followed the following link to set up the spark clusters. After successfully setting up the spark clusters I wanted to connect it to ...
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27 views
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32 views
How to read binary video format in HDFS using pyspark?
We want to work on detection of pedestrians in a video using ML algorithm.But the video is in the HDFS file system.How can we read the binary video file format from HDFS using spark?
Please help me ...
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29 views
How to score AFT survival model in pyspark?
I am using AFTSurvivalRegression package in pyspark. I have a label which is time and censor which is 1 or 0 for those event that already happened or not as well as some features. I plugged them in ...
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16 views
how to run pyspark on Hadoop cluster, cache data, then read file using pandas on local machine via its URI?
I connect to a Hadoop cluster via vpn. I want to execute a script that makes sql call and saves the data to a file on the remote machine, then using its URI I want to read on my local running Jupiter ...
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1answer
25 views
Regarding join in pyspark
Given a rdd in pyspark, $A=[(0, 1), (1, 2), (1, 3), (3, 0)]$
I am trying to find self join of A such that the second element of previous pair is equal to first element of next pair i.e.
$...
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34 views
sorting pyspark dataframe
I'm sorting a pyspark DataFrame in databricks by df.sort(desc('x')). However, when I look at the DataFrame by display(df), I don't see the DataFrame being sorted in 'x'. What could be the reason?
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108 views
Python data cleaning for CSV using Pandas and PySpark and mapping to JSON in AWS ETL Glue Environment
I have recently started working on some ETL work and wanted some guidance in this area related to data cleaning from CSV to JSON mapping using AWS Glue, Python (pandas, pyspark).
Question
Need a ...
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1answer
244 views
PicklingError: Could not serialize object: TypeError: can't pickle fasttext_pybind.fasttext objects
I built a fasttext classification model in order to do sentiment analysis for facebook comments (using pyspark 2.4.1 on windows). When I use the prediction model function to predict the class of a ...
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58 views
Pyspark: Filter dataframe based on separate specific conditions
How can I select only certain entries that match my condition and from those entries, filter again using regex?
For instance, I have this dataframe (df)
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29 views
Where is $SPARK_HOME on an EC2 instance?
I am working on an EC2 instance with anaconda and pyspark pre-installed. My $SPARK_HOME variable is not set. Any ideas on how to locate my spark home?
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2answers
56 views
Record Linkage problem
I am building Matching Alogoritm using ML.Project is to match Internal customer data with external customer data.Features are names,address,city,state and zip.
We create pairs between data sets and ...
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5 views
PCAModel and PipelineModel, how to get explainedVariance
in pyspark PCAModel contains explainedVariance() method , but once you use Pipeline and specify PCA as a "stage", you will get a PipelineModel as an output and this one does not contain ...
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64 views
Pyspark Pipeline Custom Transformer
I'm having some trouble understanding the creation of custom transformers for Pyspark pipelines.
I am writing a custom transformer that will take the dataframe column Company and remove stray commas:
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15 views
Data sharing between Custom Tranformer and estimator in pyspark
Using Titanic Dataset for classification. Created custom Estimator and transformer for pipeline. some of logical operation need to be done in fit() method and data ...
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39 views
I got a overall mean average precision score of 0 for a recommendation engine
I just wanted to know if receiving an overall MAP score of 0 in a recommendation engine was possible, or a sign that my calculation or my logic for the engine was wrong.
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33 views
Code completion and suggestion EMR Notebook
I Created an EMR Cluster with Pyspark and connected to its notebook.
However i noticed there's no code completion neither method documentation.
Has anyone ever had the same issue? Didi you solve it?
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2answers
329 views
Model ensemble with Spark or Scikit Learn
I am using Spark MLLib to make prediction and I would like to know if it is possible to create your custom Estimators.
Here is a reproducible of what I would like my model to do with the Spark api
<...
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150 views
Getting parameters of the best model with crossvalidation in with SparkMLLib
I am having trouble accessing the parameters of estimators of model in SparkMLlib. More precisely my problem is:
I have a logistic regression model for which I want to find the best regularization ...
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2answers
274 views
K-modes implementation in pyspark
I'm looking for an implementation of k-modes in pyspark. I found this and this as implementations.
First, I tried implementing k-modes using the first link and faced issues. So I went ahead and tried ...
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43 views
Obtain learning curve of Gradient Boosted Tree model in PySpark
Currently there seems to be no method in PySpark of checkpointing the performance of a model at each gradient update. Is there a way to get the performance of a model at each gradient update so that a ...
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1answer
65 views
Null predictions for ALS in Pyspark
I am trying to read from my dataset which has three coloumns. (User, Repository and Number of Stars)
In[10]
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52 views
Can we use gunicorn to deploy pyspark models?
I have created a pyspark model and want to deploy it as a real time application. I am using Flask to handle requests and gunicorn to handle multiple requests by increasing workers and threads. To run ...
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1answer
962 views
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2answers
314 views
PySpark v Pandas Dataframe Memory Issue
Suppose I have a csv file with 20k rows, which I import into Pandas dataframe. I then run models like Random Forest or Logistic Regression from sklearn package and it runs fine. However, when I import ...
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152 views
What is the difference between PySpark's featuresCol, labelCol, predictionCol, and probabilityCol?
I am attempting to train a random forest classifier (pyspark.ml.classification.RandomForestClassifier) on a large dataset (~70gb). However, I am not sure what to ...
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1answer
330 views
Using keras tokenizer on Spark DataFrame. Column is not iterable [closed]
I am having trouble using the Tokenizer
The code is
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161 views
alternatives to pyspark to query a csv file locally (no distributed computation needed)
I am reading a csv file with pyspark to extract some information from it. I am running pyspark locally and I do not need distributed computation. On the contrary I need some plotting library such as ...
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Is there a built-in pyspark function for the paradigm union(filter, take)? [closed]
Essentially, filtering by key, taking a specific number (based on key) from the DataFrame, and unioning these results for a number of values.
For example,
...
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1answer
52 views
Best Data Science & Machine Learning Conferences 2019? [closed]
What are the best data science conferences you have attended? I am looking for a conference that will help me further develop my Data Science and Machine Learning competencies. Topics that are ...
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2answers
671 views
Why is there a difference of “ML” vs “MLLIB” in Apache Spark's documentation?
I am trying to figure out which pyspark library to use with Word2Vec and I'm presented with two options according to the pyspark documentation.
https://spark.apache.org/docs/2.2.0/mllib-feature-...
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1answer
367 views
cosine similarity between items (purchase data) and normalisation
I'm using IndexedRowMatrix which represents the products's user purchase behaviours and in order to build product recommendations, I use cosine similarity to calculate similarities between products. ...
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1answer
829 views
Accumulators in Spark (PySpark) without global variables?
BACKGROUND
Consider the following textbook example which uses accumulators to add vectors.
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1answer
2k views
PySpark: java.io.EOFException
System:
1 name node, 4 cores, 16 GB RAM
1 master node, 4 cores, 16 GB RAM
6 data nodes, 4 cores, 16 GB RAM each
6 worker nodes, 4 cores, 16 GB RAM each
around 5 Terabytes of storage space
The data ...
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3answers
3k views
Reliable way to verify Pyspark data frame column type
If I read data from a CSV, all the columns will be of "String" type by default. Generally, I inspect the data using the following functions which gives an overview of the data and its types
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1answer
4k views
Replacing null with average in pyspark
I have a problem during upsampling operation in PySpark. My dataframe is:
...
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1answer
5k views
Plotting in PySpark?
I have been searching for methods to plot in PySpark.
I couldn't find any resource on plotting data residing in DataFrame in PySpark. The only methods which are listed are:
through method ...
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2answers
90 views
Apache Spark Understanding
I have read a lot about Apache Spark. About RDD, DataFrames etc etc. But I haven't come across a simple explanation as to why and where should we be using Apache Spark? If my primary goal is machine/...
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0answers
492 views
Frequent itemset vs. frequent sequence mining algorithms on variables with an inherent order
I've been using Pyspark's PrefixSpan algorithm to mine sequences of variables with an inherent order (bus stops). I know that PrefixSpan takes into consideration the order of the items it is fed, ...
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2answers
412 views
k-means|| in PySpark
I'm trying to apply k-means$\|$ clustering in PySpark.
According to this paper, there is an oversampling factor, $l$, that would affect the model's cost.
I couldn't find any parameter regarding ...
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0answers
8k views
Adding multiple columns to spark dataframe
I would like to add several columns to a spark (actually pyspark) dataframe , these columns all being functions of several input columns in the df. There seems to be no 'add_columns' in spark, and ...
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0answers
137 views
Running H2O in databricks
I'm trying to run H2O in databricks. However, when I do the following:
hc = pysparkling.H2OContext.getOrCreate(spark)
I get the following error:
java.lang.AbstractMethodError
Does anyone know what ...
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2answers
518 views
Exponential runtime on distance matrix
I have an exploratory script running a Databricks notebook that performs a simple arithmetic function (Pythagorean theorem) on all possible pairwise combinations of a list of pairs of floats (akin to ...
