Package 'iForecast'

Title: Machine Learning Time Series Forecasting
Description: Compute static, onestep and multistep time series forecasts for machine learning models.
Authors: Ho Tsung-wu [aut, cre]
Maintainer: Ho Tsung-wu <[email protected]>
License: GPL (>= 2)
Version: 1.0.9
Built: 2024-12-01 08:28:04 UTC
Source: CRAN

Help Index


Economic and Financial Data Sets

Description

ES_15m is 15-min realized absolute variance of e-mini S&P 500. macrodata contains monthly US unemployment(unrate), ES_Daily is daily realized absolute variance of e-mini S&P 500. macrodata contains monthly US unemployment(unrate) and and year-to-year changes in three regional business cycle indices (OECD, NAFTA, and G7). bc contains monthly business cycle data, bc is binary indicator(0=recession, 1=boom) of Taiwan's business cycle phases, IPI_TWN is industrial production index of Taiwan, LD_OECD, LD_G7, and LD_NAFTA are leading indicators of OECD, G7 and NAFTA regions; all four are monthly rate of changes.

Usage

data(ES_15m)
data(macrodata)
data(ES_Daily)
data(bc)

Value

an object of class "zoo".


Extract predictions and class probabilities from train objects

Description

It generates both the static and recursive time series plots of machine learning prediction object generated by ttsCaret, ttsAutoML and ttsLSTM.

Usage

iForecast(Model,newdata,type)

Arguments

Model

Object of trained model.

newdata

The dataset for pediction, the column names must be the same as the trained data.

type

If type="static", it computes the (static) forecasting values of insample model fit. If type="dynamic", it iteratively computes the multistep forecasting values given the insample estimated model. For dynamic forecasts, AR term is required.

Details

This function generates forecasts of ttsCaret,ttsAutoML, and ttsLSTM.

Value

prediction

The forecasted time series target variable. For binary case, it returns both porbabilities and class.

Author(s)

Ho Tsung-wu <[email protected]>, College of Management, National Taiwan Normal University.

Examples

# Cross-validation takes time, example below is commented.
## Machine Learning by library(caret)
#Case 1. Low frequency, regression type
data("macrodata")
dep <- macrodata[569:669,"unrate",drop=FALSE]
ind <- macrodata[569:669,-1,drop=FALSE]
train.end <- "2018-12-01"# Choosing the end dating of train

models <- c("svm","rf","rpart")[1]
type <- c("none","trend","season","both")[1]
#output <- ttsCaret(y=dep, x=ind, arOrder=c(1), xregOrder=c(1),
# method=models, tuneLength =1, train.end, type=type,resampling="cv",preProcess = #"center")
# testData1 <- window(output$data,start="2019-01-01",end=end(output$data))
#P1 <- iForecast(Model=output,newdata=testData1,type="static")
#P2 <- iForecast(Model=output,newdata=testData1,type="dynamic")

#tail(cbind(testData1[,1],P1))
#tail(cbind(testData1[,1],P2))

#Case 2. Low frequency, binary type
data(bc) #binary dependent variable, business cycle phases
dep=bc[,1,drop=FALSE]
ind=bc[,-1]

train.end=as.character(rownames(dep))[as.integer(nrow(dep)*0.8)]
test.start=as.character(rownames(dep))[as.integer(nrow(dep)*0.8)+1]

#output = ttsCaret(y=dep, x=ind, arOrder=c(1), xregOrder=c(1), method=models,
#                   tuneLength =10, train.end, type=type)

#testData1=window(output$data,start=test.start,end=end(output$data))

#head(output$dataused)
#P1=iForecast(Model=output,newdata=testData1,type="static")
#P2=iForecast(Model=output,newdata=testData1,type="dynamic")

#tail(cbind(testData1[,1],P1),10)
#tail(cbind(testData1[,1],P2),10)

Defunct functions in package ‘iForecast’

Description

These functions are defunct and no longer available.

Details

Defunct function is: ttsAutoML New function is: tts.autoML


Defunct functions in package ‘iForecast’

Description

These functions are defunct and no longer available.

Details

Defunct function is: ttsCaret New function is: tts.caret


Defunct functions in package ‘iForecast’

Description

These functions are defunct and no longer available.

Details

Defunct functions are: ttsLSTM


Rolling timeframe for time series anaysis

Description

It extracts time stamp from a timeSeries object and separates the time into in-sample training and out-of-sample validation ranges.

Usage

rollingWindows(x,estimation="18m",by = "6m")

Arguments

x

The time series matrix (vector) with timeSeries or zoo format of "

estimation

The range of insample estimation period, the default is 18 months(18m), where the k-fold cross-section is performed. Week and day are also supported (see example).

by

The range of out-of-sample validation/testing period, the default is 6 months(6m).Week and day are also supported (see example).

Details

This function is similar to the backtesting framework in portfolio analysis. Rolling windows fixes the origin and the training sample grows over time, moving windows can be achieved by placing window() on dependent variable at each iteration.

Value

window

The time labels of from and to

.

Author(s)

Ho Tsung-wu <[email protected]>, College of Management, National Taiwan Normal University.

Examples

data(macrodata)
y=macrodata[,1,drop=FALSE]
timeframe=rollingWindows(y,estimation="300m",by="6m")
#estimation="300m", because macrodata is monthly
FROM=timeframe$from
TO=timeframe$to

data(ES_Daily)
y=ES_Daily[,1,drop=FALSE]
timeframe=rollingWindows(y,estimation  ="60w",by="1w")
#60 weeks as estimation windowand move by 1 week.

FROM=timeframe$from
TO=timeframe$to

y=ES_Daily[,1,drop=FALSE]
timeframe=rollingWindows(y,estimation  ="250d",by="1d")
#250-day as estimation window and move by 1 days.

Train time series by automatic machine learning of h2o provided by H2O.ai

Description

It generates both the static and recursive time series plots of H2O.ai object generated by package h2o provided by H2O.ai.

Usage

tts.autoML(y,x=NULL,train.end,arOrder=2,xregOrder=0,maxSecs=30)

Arguments

y

The time series object of the target variable, or the dependent variable, with timeSeries or zoo format, must have dimension. y can be either binary or continuous. Time format must be "

x

The time series matrix of input variables, or the independent variables, with timeSeries or zoo format. Time format must be "

train.end

The end date of training data, must be specificed. The default dates of train.start and test.end are the start and the end of input data; and the test.start is the 1-period next of train.end.

arOrder

The autoregressive order of the target variable, which may be sequentially specifed like arOrder=1:5; or discontinuous lags like arOrder=c(1,3,5); zero is not allowed.

xregOrder

The distributed lag structure of the input variables, which may be sequentially specifed like xregOrder=1:5; or discontinuous lags like xregOrder=c(0,3,5); zero is allowed since contemporaneous correlation is allowed.

maxSecs

The maximal run time specified, in seconds. Default=20.

Details

This function calls the h2o.automl function from package h2o to execute automatic machine learning estimation. When execution finished, it computes two types of time series forecasts: static and recursive. The procedure of h2o.automl automatically generates a lot of time features.

Value

output

Output object generated by train function of caret.

arOrder

The autoregressive order of the target variable used.

data

The dataset of imputed.

dataused

The data used by arOrder, xregOrder

Author(s)

Ho Tsung-wu <[email protected]>, College of Management, National Taiwan Normal University.

Examples

# Cross-validation takes time, example below is commented.
data("macrodata")
dep<-macrodata[,"unrate",drop=FALSE]
ind<-macrodata[,-1,drop=FALSE]

# Choosing the dates of training and testing data
train.end<-"2008-12-01"

#autoML of H2O.ai

#autoML <- tts.autoML(y=dep, x=ind, train.end,arOrder=c(2,4),
# xregOrder=c(0,1,3), maxSecs =30)
#testData2 <- window(autoML$dataused,start="2009-01-01",end=end(autoML$data))
#P1<-iForecast(Model=autoML,newdata=testData2,type="static")
#P2<-iForecast(Model=autoML,newdata=testData2,type="dynamic")

#tail(cbind(testData2[,1],P1))
#tail(cbind(testData2[,1],P2))

Train time series by caret and produce two types of time series forecasts: static and dynamic

Description

It generates both the static and dynamic time series plots of machine learning prediction object generated by package caret.

Usage

tts.caret(
  y,
  x=NULL,
  method,
  train.end,
  arOrder=2,
  xregOrder=0,
  type,
  tuneLength =10,
  preProcess = NULL,
  resampling="boot",
  Number=NULL,
  Repeat=NULL)

Arguments

y

The time series object of the target variable, or the dependent variable, with timeSeries or zoo format, must have dimension. y can be either binary or continuous.Timestamp format must be "

x

The time series matrix of input variables, or the independent variables, with timeSeries or zoo format.Timestamp format must be "

method

The train_model_list of caret. While using this, make sure that the method allows regression. Methods in c("svm","rf","rpart","gamboost","BstLm","bstSm","blackboost") are feasible.

train.end

The end date of training data, must be specificed.The default dates of train.start and test.end are the start and the end of input data; and the test.start is the 1-period next of train.end.

arOrder

The autoregressive order of the target variable, which may be sequentially specifed like arOrder=1:5; or discontinuous lags like arOrder=c(1,3,5); zero is not allowed.

xregOrder

The distributed lag structure of the input variables, which may be sequentially specifed like xregOrder=0:5; or discontinuous lags like xregOrder=c(0,3,5); zero is allowed since contemporaneous correlation is allowed.

type

The additional input variables. We have four selection:
"none"=no other variables,
"trend"=inclusion of time dummy,
"season"=inclusion of seasonal dummies,
"both"=inclusion of both trend and season. No default.

tuneLength

The same as the length specified in train function of package caret.

preProcess

Whether to pre-process the data, current possibilities are "BoxCox", "YeoJohnson", "expoTrans", "center", "scale", "range", "knnImpute", "bagImpute", "medianImpute", "pca", "ica" and "spatialSign".The default is no pre-processing.

resampling

The method for resampling, as trainControl function list in package caret. The default is "boot" for bootstrapping with 25 replications. Current choices are c("cv","boot","repeatedcv","LOOCV") where "cv" is K-fold CV with a default K=10 or specified by the "Number" below, "LOOCV" denotes the leave-one-out CV

Number

The number of K for K-Fold CV, default (NULL) is 10; for "boot" option, the default number of replications is 25

Repeat

The number for the repeatition for "repeatedcv".

Details

This function calls the train function of package caret to execute estimation. When execution finished, we compute two types of time series forecasts: static and recursive.

Value

output

Output object generated by train function of caret.

arOrder

The autoregressive order of the target variable used.

data

The dataset of imputed.

dataused

The data used by arOrder, xregOrder, and type.

training.Pred

All tuned prediction values of training data, using besTunes to extract the best prediction.

Author(s)

Ho Tsung-wu <[email protected]>, College of Management, National Taiwan Normal University.

Examples

# Cross-validation takes time, example below is commented.
## Machine Learning by library(caret)
library(zoo)
#Case 1. Low frequency
data("macrodata")
dep <- macrodata[569:669,"unrate",drop=FALSE]
ind <- macrodata[569:669,-1,drop=FALSE]
train.end <- "2018-12-01"# Choosing the end dating of train

models <- c("glm","knn","nnet","rpart","rf","svm","enet","gbm","lasso","bridge")[2]
type <- c("none","trend","season","both")[1]
output <- tts.caret(y=dep, x=NULL, arOrder=c(1), xregOrder=c(1),
 method=models, tuneLength =1, train.end, type=type,
 resampling=c("boot","cv","repeatedcv")[1],preProcess = "center")

 testData1 <- window(output$dataused,start="2019-01-01",end=end(dep))
P1 <- iForecast(Model=output,newdata=testData1,type="static")
P2 <- iForecast(Model=output,newdata=testData1,type="dynamic")

tail(cbind(testData1[,1],P1,P2))

#Case 2. High frequency
#head(ES_15m)
#head(ES_Daily)
#dep <- ES_15m #SP500 15-minute realized absolute variance
#ind <- NULL
#train.end <- as.character(rownames(dep))[as.integer(nrow(dep)*0.9)]

#models<-c("svm","rf","rpart","gamboost","BstLm","bstSm","blackboost")[1]
#type<-c("none","trend","season","both")[1]
# output <- tts.caret(y=dep, x=ind, arOrder=c(3,5), xregOrder=c(0,2,4),
# method=models, tuneLength =10, train.end, type=type,
# resampling=c("boot","cv","repeatedcv")[2],preProcess = "center")
#testData1<-window(output$data,start="2009-01-01",end=end(output$data))
#P1<-iForecast(Model=output,newdata=testData1,type="static")
#P2<-iForecast(Model=output,newdata=testData1,type="dynamic")