vDataFrame#
- class verticapy.vDataFrame(input_relation: str | list | dict | DataFrame | ndarray | TableSample, usecols: str | list[str] | None = None, schema: str | None = None, external: bool = False, symbol: str = '$', sql_push_ext: bool = True, _empty: bool = False, _is_sql_magic: int = 0, _clean_query: bool = True)#
An object that records all user modifications, allowing users to manipulate the relation without mutating the underlying data in Vertica. When changes are made, the
vDataFrame
queries the Vertica database, which aggregates and returns the final result. ThevDataFrame
creates, for each column of the relation, a Virtual Column (vDataColumn
) that stores the column alias an all user transformations.Parameters#
- input_relation: str | TableSample | pandas.DataFrame | list | numpy.ndarray | dict, optional
If the input_relation is of type
str
, it must represent the relation (view, table, or temporary table) used to create the object. To get a specificschema
relation, your string must include both the relation and schema:'schema.relation'
or'"schema"."relation"'
. Alternatively, you can use the ‘schema’ parameter, in which case theinput_relation
must exclude theschema
name. It can also be the SQL query used to create thevDataFrame
. If it is apandas.DataFrame
, a temporary local table is created. Otherwise, the vDataFrame is created using the generated SQL code of multiple UNIONs.- usecols: SQLColumns, optional
When
input_relation
is not an array-like type: List of columns used to create the object. As Vertica is a columnar DB, including less columns makes the process faster. Do not hesitate to exclude useless columns. Otherwise: List of column names.- schema: str, optional
The schema of the relation. Specifying a schema allows you to specify a table within a particular schema, or to specify a
schema
andrelation
name that contain period ‘.’ characters. If specified, theinput_relation
cannot include aschema
.- external: bool, optional
A boolean to indicate whether it is an external table. If set to
True
, a Connection Identifier Database must be defined.- symbol: str, optional
Symbol used to identify the external connection. One of the following:
"$", "€", "£", "%", "@", "&", "§", "?", "!"
- sql_push_ext: bool, optional
If set to
True
, the externalvDataFrame
attempts to push the entire query to the external table (only DQL statements - SELECT; for other statements, use SQL Magic directly). This can increase performance but might increase the error rate. For instance, some DBs might not support the same SQL as Vertica.
Attributes#
- vDataColumns
vDataColumn
Each
vDataColumn
of thevDataFrame
is accessible by specifying its name between brackets. For example, to access thevDataColumn
“myVC”:vDataFrame["myVC"]
.
Examples#
In this example, we will look at some of the ways how we can create a
vDataFrame
.From
dictionary
From
numpy.array
From
pandas.DataFrame
From SQL Query
From a table
After that we will also look at the mathematical operators that are available:
Pandas-Like
SQL-Like
Lastly, we will look at some examples of applications of functions that be applied directly on the
vDataFrame
.
Let’s begin by importing VerticaPy.
import verticapy as vp
Hint
By assigning an alias to
verticapy
, we mitigate the risk of code collisions with other libraries. This precaution is necessary because verticapy uses commonly known function names like “average” and “median”, which can potentially lead to naming conflicts. The use of an alias ensures that the functions fromverticapy
are used as intended without interfering with functions from other libraries.Dictionary#
This is the most direct way to create a
vDataFrame
:vdf = vp.vDataFrame( { "cats": ["A", "B", "C"], "reps": [2, 4, 8], }, )
AbccatsVarchar(1)100%123repsInteger100%1 A 2 2 B 4 3 C 8 Numpy Array#
We can also use a
numpy.array
:import numpy as np vdf = vp.vDataFrame( np.array( [ [1, 2, 3], [4, 5, 6], [7, 8, 9], ], ), usecols = [ "col_A", "col_B", "col_C", ], )
123col_AInteger100%... 123col_BInteger100%123col_CInteger100%1 1 ... 2 3 2 4 ... 5 6 3 7 ... 8 9 Pandas DataFrame#
We can also use a
pandas.DataFrame
object:# Import Pandas library import pandas as pd # Create the data dictionary data = { 'Name': ['John', 'Ali', 'Pheona'], 'Age': [25, 30, 22], 'City': ['New York', 'Gaza', 'Los Angeles'], } # Create the Pandas DataFrame object df = pd.DataFrame(data) # Create a vDataFrame vdf = vp.vDataFrame(df)
AbcNameVarchar(20)100%... 123AgeInt100%AbcCityVarchar(22)100%1 Ali ... 30 Gaza 2 John ... 25 New York 3 Pheona ... 22 Los Angeles SQL Query#
We can also use a SQL Query:
# Write a SQL Query to fetch three rows from the Titanic table sql_query = "SELECT age, sex FROM public.titanic LIMIT 3;" # Create a vDataFrame vdf = vp.vDataFrame(sql_query)
123ageNumeric(8)100%AbcsexVarchar(20)100%1 2.0 female 2 30.0 male 3 25.0 female Table#
A table can also be directly ingested:
# Create a vDataFrame from the titanic table in public schema vdf = vp.vDataFrame("public.titanic")
123pclassInt100%... 123survivedInt100%Abchome.destVarchar(100)57%1 1 ... 0 Montreal, PQ / Chesterville, ON 2 1 ... 0 Montreal, PQ / Chesterville, ON 3 1 ... 0 Montreal, PQ / Chesterville, ON 4 1 ... 0 Belfast, NI 5 1 ... 0 Montevideo, Uruguay 6 1 ... 0 New York, NY 7 1 ... 0 New York, NY 8 1 ... 0 Montreal, PQ 9 1 ... 0 Winnipeg, MN 10 1 ... 0 San Francisco, CA 11 1 ... 0 Trenton, NJ 12 1 ... 0 London / Winnipeg, MB 13 1 ... 0 Pomeroy, WA 14 1 ... 0 Omaha, NE 15 1 ... 0 Philadelphia, PA 16 1 ... 0 Washington, DC 17 1 ... 0 [null] 18 1 ... 0 New York, NY 19 1 ... 0 Montevideo, Uruguay 20 1 ... 0 Montevideo, Uruguay Mathematical Operators#
We can use all the common mathematical operators on the
vDataFrame
.Pandas-Like#
First let us re-create a simple
vDataFrame
:vdf = vp.vDataFrame( { "cats": ["A", "B", "C"], "reps": [2, 4, 8], }, )
In order to search for a specific string value of a specific column:
result = vdf[vdf["cats"] == "A"]
AbccatsVarchar(1)100%123repsInteger100%1 A 2 Similarly we can perform a mathematical operations as well for numerical columns:
result = vdf[vdf["reps"] > 2]
AbccatsVarchar(1)100%123repsInteger100%1 B 4 2 C 8 Both operators could also be combined:
result = vdf[vdf["reps"] > 2][vdf["cats"] == "C"]
AbccatsVarchar(1)100%123repsInteger100%1 C 8 We can also perform mathematical calculations on the elements inside the
vDataFrame
quite conveniently:vdf["new"] = abs(vdf["reps"] * 4 - 100)
AbccatsVarchar(1)100%... 123repsInteger100%123newInteger100%1 A ... 2 92 2 B ... 4 84 3 C ... 8 68 SQL-Like#
SQL queries can be directly applied on the
vDataFrame
usingStringSQL
. This adds a new level of flexibility to thevDataFrame
.StringSQL
allows the user to generate formatted SQL queries in a string form. Since any SQL query in string format can be passed to thevDataFrame
, you can seamlessly pass the output ofStringSQL
directly to thevDataFrame
.# Create the SQL Query using StringSQL sql_query = vp.StringSQL("reps > 2") # Get the output as a vDataFrame result = vdf[sql_query]
AbccatsVarchar(1)100%... 123repsInteger100%123newInteger100%1 B ... 4 84 2 C ... 8 68 Note
Have a look at
StringSQL
for more details.Another example of a slightly advanced SQL Query could be:
# Create the SQL Query using StringSQL sql_query = vp.StringSQL("reps BETWEEN 3 AND 8 AND cats = 'B'") # Get the output as a vDataFrame result = vdf[sql_query]
AbccatsVarchar(1)100%... 123repsInteger100%123newInteger100%1 B ... 4 84
Direct Functions#
There are many methods that can be directly used by
vDataFrame
. Let us look at how conveiently we can call them. Here is an example of thevDataFrame.
describe()
method:# Import the dataset from verticapy.datasets import load_titanic # Create vDataFrame vdf = load_titanic() # Summarize the vDataFrame vdf.describe() Out[23]: None ... approx_75% max "pclass" ... 3.0 3.0 "survived" ... 1.0 1.0 "age" ... 39.0 80.0 "sibsp" ... 1.0 8.0 "parch" ... 0.0 9.0 "fare" ... 31.3875 512.3292 "body" ... 257.5 328.0 Rows: 1-7 | Columns: 9
... approx_75% max "pclass" ... 3 3 "survived" ... 1 1 "age" ... 39 80 "sibsp" ... 1 8 "parch" ... 0 9 "fare" ... 31.3875 512.3292 "body" ... 257.5 328 Note
Explore
vDataFrame
andvDataColumn
different methods to see more examples.See also
vDataColumn
: Columns ofvDataFrame
object.
- class verticapy.vDataColumn(alias: str, transformations: list | None = None, parent: vDataFrame | None = None, catalog: dict | None = None)#
Python object that stores all user transformations. If the
vDataFrame
represents the entire relation, avDataColumn
can be seen as one column of that relation. Through its abstractions,vDataColumn
simplify several processes.Parameters#
- alias: str
vDataColumn
alias.- transformations: list, optional
List of the different transformations. Each transformation must be similar to the following:
(function, type, category)
- parent: vDataFrame, optional
Parent of the
vDataColumn
. OnevDataFrame
can have multiple childrenvDataColumn
, whereas onevDataColumn
can only have one parent.- catalog: dict, optional
Catalog where each key corresponds to an aggregation.
vDataColumn
will memorize the already computed aggregations to increase performance. The catalog is updated when the parentvDataFrame
is modified.
Attributes#
- alias, str:
vDataColumn
alias.- catalog, dict:
Catalog of pre-computed aggregations.
- parent, vDataFrame:
Parent of the
vDataColumn
.- transformations, str:
List of the different transformations.
Examples#
Let’s begin by importing VerticaPy.
import verticapy as vp
Hint
By assigning an alias to
verticapy
, we mitigate the risk of code collisions with other libraries. This precaution is necessary because verticapy uses commonly known function names like “average” and “median”, which can potentially lead to naming conflicts. The use of an alias ensures that the functions fromverticapy
are used as intended without interfering with functions from other libraries.Let’s create a
vDataFrame
with twovDataColumn
:vdf = vp.vDataFrame( { "cats": ["A", "B", "C"], "reps": [2, 4, 8], }, )
AbccatsVarchar(1)100%123repsInteger100%1 A 2 2 B 4 3 C 8 “cats” and “reps” are
vDataColumn
objects. They can be accessed the same way as adictionary
or apandas.DataFrame
. They represent the columns of the entire relation.For example, the following code will access the
vDataColumn
“cats”:vdf["cats"]
Note
vDataColumn
are columns inside avDataFrame
; they have their own methods but cannot exist without a parentvDataFrame
. Please refer tovDataFrame
to see an entire example.See also
vDataFrame
: Main VerticaPy dataset object.
Plotting#
There are three main plotting libraries available in VerticaPy:
Plotly
Highcharts
Matplotlib
To access the bases classes of all the plotting libraries click the dropdown button below.
Note
The documentation for these classes is provided solely to enhance the user’s understanding of the implementations. Users are not required to interact directly with these classes, and we do not recommend doing so.
Plotting Base Classes
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General#
vDataFrame.func(...)
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Draws the bar chart of the input vDataColumns based on an aggregation. |
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Draws the horizontal bar chart of the input |
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Draws the Box Plot of the input vDataColumns. |
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Draws the contour plot of the input function using two input vDataColumns. |
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Draws the vDataColumns Density Plot. |
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Draws the Heatmap of the two input vDataColumns. |
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Draws the Hexbin of the input vDataColumns based on an aggregation. |
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Draws the histograms of the input vDataColumns based on an aggregation. |
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Draws the global outliers plot of one or two columns based on their ZSCORE. |
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Draws the nested pie chart of the input |
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Draws the pivot table of one or two columns based on an aggregation. |
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Draws the time series. |
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Draws the scatter plot of the input vDataColumns. |
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Draws the scatter matrix of the vDataFrame. |
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Returns the chi-square term using the pivot table of the response |
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Draws the range plot of the input vDataColumns. |
vDataFrame[].func(...)
|
Draws the bar chart of the vDataColumn based on an aggregation. |
|
Draws the horizontal bar chart of the vDataColumn based on an aggregation. |
|
Draws the Time Series of the vDataColumn. |
|
Draws the box plot of the vDataColumn. |
|
Draws the vDataColumn Density Plot. |
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Draws the histogram of the input vDataColumn based on an aggregation. |
|
Draws the pie chart of the vDataColumn based on an aggregation. |
|
Draws the Time Series of the vDataColumn. |
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Draws the range plot of the vDataColumn. |
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Draws the spider plot of the input vDataColumn based on an aggregation. |
Animated#
vDataFrame.func(...)
|
Draws the animated bar chart (bar race). |
|
Draws the animated pie chart. |
|
Draws the animated line plot. |
|
Draws the animated scatter plot. |
Descriptive Statistics#
vDataFrame.func(...)
|
Utilizes the |
|
Aggregates the vDataFrame using the input functions. |
|
Applies the |
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Uses the |
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This operation aggregates the vDataFrame using the |
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This operation aggregates the vDataFrame using the |
|
Performs aggregation on the vDataFrame using a list of aggregate functions, including |
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This function aggregates the vDataFrame using multiple statistical aggregations such as minimum (min), maximum (max), median, cardinality (unique), and other relevant statistics. |
|
This function returns a list or set of values that occur more than once within the dataset. |
|
Calculates the kurtosis of the vDataFrame to obtain a measure of the data's peakedness or tailness. |
|
Utilizes the |
|
Aggregates the vDataFrame by applying the |
|
Aggregates the vDataFrame using the |
|
Aggregates the vDataFrame by applying the |
|
When aggregating the vDataFrame using nunique (cardinality), VerticaPy employs the COUNT DISTINCT function to determine the number of unique values in a particular column. |
|
Aggregates the vDataFrame by applying the |
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Aggregates the vDataFrame using specified |
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Computes the score using the input columns and the input metric. |
|
Leverages the |
|
Utilizes the |
|
Aggregates the vDataFrame using |
|
Aggregates the vDataFrame using |
|
Aggregates the vDataFrame using |
vDataFrame[].func(...)
|
Utilizes the |
|
Aggregates the vDataFrame using the input functions. |
|
This operation aggregates the vDataFrame using the |
|
This operation aggregates the vDataFrame using the |
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This function aggregates the vDataColumn using multiple statistical aggregations such as minimum (min), maximum (max), median, cardinality (unique), and other relevant statistics. |
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This function returns the distinct categories or unique values within a vDataColumn. |
|
Calculates the kurtosis of the vDataColumn to obtain a measure of the data's peakedness or tailness. |
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Utilizes the |
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Aggregates the vDataFrame by applying the 'MAX' aggregation, which calculates the maximum value, for the input column. |
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Aggregates the vDataFrame using the |
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Aggregates the vDataFrame by applying the |
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This function returns the nth most frequently occurring element in the vDataColumn. |
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Returns the |
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Returns the |
|
When aggregating the vDataFrame using nunique (cardinality), VerticaPy employs the COUNT DISTINCT function to determine the number of unique values in particular columns. |
|
Aggregates the vDataColumn by applying the |
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Aggregates the vDataColumn using a specified |
|
Leverages the |
|
Utilizes the |
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Aggregates the vDataFrame using |
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Aggregates the vDataFrame using |
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This function returns the k most frequently occurring elements in a column, along with their distribution expressed as percentages. |
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This function returns the k most frequently occurring elements in a column, along with information about how often they occur. |
|
Aggregates the vDataFrame using |
Correlation & Dependency#
General#
vDataFrame.func(...)
|
Calculates the correlations between the specified vDataColumn and its various time lags. |
|
Calculates the Correlation Matrix for the vDataFrame. |
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Computes the Correlation Coefficient between two input vDataColumns, along with its associated p-value. |
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Computes the covariance matrix of the vDataFrame. |
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Calculates the Information Value (IV) Table, a powerful tool for assessing the predictive capability of an independent variable concerning a dependent variable. |
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Computes the partial autocorrelations of the specified vDataColumn. |
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Calculates the regression matrix for the given vDataFrame. |
vDataFrame[].func(...)
|
Calculates the Information Value (IV) / Weight Of Evidence (WOE) Table. |
Time-series#
Preprocessing#
Encoding#
vDataFrame.func(...)
|
Creates a new feature by evaluating on provided conditions. |
|
Encodes the vDataColumns using the One Hot Encoding algorithm. |
vDataFrame[].func(...)
|
Discretizes the vDataColumn using the input list. |
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Encodes the vDataColumn using a user-defined encoding. |
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Discretizes the vDataColumn using the input method. |
Encodes the vDataColumn using a bijection from the different categories to [0, n - 1] (n being the vDataColumn cardinality). |
|
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Encodes the vDataColumn using the average of the response partitioned by the different vDataColumn categories. |
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Encodes the vDataColumn with the One-Hot Encoding algorithm. |
Dealing With Missing Values#
vDataFrame.func(...)
|
Filters the specified vDataColumns in a vDataFrame for missing values. |
|
Fills missing elements in |
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Computes a regular time interval vDataFrame by interpolating the missing values using different techniques. |
Duplicate Values#
vDataFrame.func(...)
|
Filters the duplicates using a partition by the input vDataColumns. |
Normalization and Global Outliers#
vDataFrame.func(...)
vDataFrame[].func(...)
|
Clips the vDataColumn by transforming the values less than the lower bound to the lower bound value and the values higher than the upper bound to the upper bound value. |
|
Fills the vDataColumns outliers using the input method. |
|
Scales the input vDataColumns using the input method. |
Data Types Conversion#
Formatting#
vDataFrame.func(...)
|
Method used to format the input columns by using the vDataFrame columns' names. |
|
Returns the matching index. |
|
Method used to check if the input column name is used by the vDataFrame. |
|
Merges columns with similar names. |
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Returns exploded vDataFrame of array-like columns in a vDataFrame. |
Splitting into Train/Test#
vDataFrame.func(...)
|
Creates two vDataFrames (train/test), which can be used to evaluate a model. |
Working with Weights#
vDataFrame.func(...)
|
Duplicates the |
Complete Disjunctive Table#
vDataFrame.func(...)
|
Returns the complete disjunctive table of the vDataFrame. |
Features Engineering#
Analytic Functions#
vDataFrame.func(...)
|
Adds a new vDataColumn to the vDataFrame by using an advanced analytical function on one or two specific vDataColumns. |
|
Computes a regular time interval vDataFrame by interpolating the missing values using different techniques. |
|
Adds a new |
Custom Features Creation#
Features Transformations#
vDataFrame.func(...)
|
Applies the absolute value function to all input vDataColumns. |
|
Applies each function of the dictionary to the input vDataColumns. |
|
Applies a function to all vDataColumns. |
|
Returns a vDataFrame containing the different product combinations of the input |
|
Swap the two input vDataColumns. |
vDataFrame[].func(...)
|
Applies the absolute value function to the input vDataColumn. |
|
Adds the input element to the vDataColumn. |
|
Applies a function to the vDataColumn. |
|
Applies a default function to the vDataColumn. |
|
Extracts a specific TS field from the vDataColumn (only if the vDataColumn type is date like). |
|
Divides the vDataColumn by the input element. |
|
Multiplies the vDataColumn by the input element. |
|
Rounds the vDataColumn by keeping only the input number of digits after the decimal point. |
|
Slices and transforms the vDataColumn using a time series rule. |
|
Subtracts the input element from the vDataColumn. |
Moving Windows#
vDataFrame.func(...)
|
Adds a new |
|
Adds a new |
|
Adds a new |
|
Adds a new |
|
Adds a new |
Working with Text#
vDataFrame.func(...)
|
Computes a new vDataColumn based on regular expressions. |
vDataFrame[].func(...)
|
Verifies if the regular expression is in each of the vDataColumn records. |
|
Computes the number of matches for the regular expression in each record of the vDataColumn. |
|
Extracts the regular expression in each record of the vDataColumn. |
|
Replaces the regular expression matches in each of the vDataColumn record by an input value. |
|
Slices the vDataColumn. |
Binary Operator Functions#
Basic Feature Selection#
vDataFrame.func(...)
|
Returns a CHAID (Chi-square Automatic Interaction Detector) tree. |
|
Function used to simplify the code. |
Join, sort and transform#
vDataFrame.func(...)
|
Merges the vDataFrame with another vDataFrame or an input relation, and returns a new vDataFrame. |
|
Returns a deep copy of the |
|
Flatten the selected VMap. |
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This method facilitates the aggregation of the vDataFrame by grouping its elements based on one or more specified criteria. |
|
Joins the |
|
Returns the Narrow Table of the vDataFrame using the input vDataColumns. |
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Returns the Pivot of the vDataFrame using the input aggregation. |
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Recommend items based on the Collaborative Filtering (CF) technique. |
|
Sorts the |
vDataFrame[].func(...)
|
Adds a copy vDataColumn to the parent vDataFrame. |
Filter and Sample#
Search#
vDataFrame.func(...)
|
Searches for elements that match the input conditions. |
Sample#
vDataFrame.func(...)
|
Downsamples the input vDataFrame. |
Balance#
vDataFrame.func(...)
|
Balances the dataset using the input method. |
Filter Columns#
vDataFrame.func(...)
vDataFrame[].func(...)
|
Drops the vDataColumn from the vDataFrame. |
|
Drops outliers in the vDataColumn. |
Filter Records#
vDataFrame.func(...)
|
Filters the vDataFrame by only keeping the records at the input time. |
|
Filters the vDataFrame by only keeping the records between two input elements. |
|
Filters the vDataFrame by only keeping the records between two input times. |
|
Filters the vDataFrame using the input expressions. |
|
Filters the vDataFrame by only keeping the first records. |
|
Checks whether specific records are in the vDataFrame and returns the new vDataFrame of the search. |
|
Filters the vDataFrame by only keeping the last records. |
vDataFrame[].func(...)
|
Checks whether specific records are in the vDataColumn and returns the new vDataFrame of the search. |
Serialization#
General Format#
vDataFrame.func(...)
|
Creates a CSV file or folder of CSV files of the current |
|
Creates a JSON file or folder of JSON files of the current |
|
Creates a SHP file of the current |
In-memory Object#
vDataFrame.func(...)
|
Converts the |
Converts the vDataFrame to a |
|
|
Converts the |
|
Converts the |
Databases#
vDataFrame.func(...)
|
Saves the |
Binary Format#
vDataFrame.func(...)
|
Saves the |
Utilities#
Information#
vDataFrame.func(...)
|
Returns the vDataFrame categorical vDataColumns. |
|
Returns the current vDataFrame relation. |
|
Returns a list of the vDataColumns of type date in the vDataFrame. |
|
Returns the different vDataColumns types. |
|
Returns True if the vDataFrame is empty. |
|
Provides information on how Vertica is computing the current |
|
Returns the vDataFrame vDataColumns. |
|
Returns the vDataFrame head. |
|
This method displays the interactive table. |
|
Returns a part of the |
|
Displays information about the different vDataFrame transformations. |
Returns the vDataFrame memory usage. |
|
|
Returns the vDataFrame expected store usage. |
|
Returns a list of names of the numerical vDataColumns in the vDataFrame. |
|
Returns the number of rows and columns of the |
|
Returns the tail of the |
vDataFrame[].func(...)
|
Returns the category of the vDataColumn. |
|
Returns the vDataColumn DB type. |
|
Returns the vDataColumn DB type. |
|
Returns a new |
|
Returns the head of the |
|
Returns a part of the |
|
Returns True if the vDataColumn is an array, False otherwise. |
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Returns True if the vDataColumn is boolean, False otherwise. |
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Returns True if the vDataColumn category is date, False otherwise. |
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Returns True if the vDataColumn is numerical, False otherwise. |
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Returns True if the vDataColumn category is VMap, False otherwise. |
Returns the vDataColumn memory usage. |
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Returns the vDataColumn expected store usage (unit: b). |
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Returns the tail of the |