Load variable once in DeployR - r

I have a model trained and stored in a file called "rpartModel.RData", in my R script to use this model in DeployR, I need to load the model every time the script is called.
There is any way to load the file only once and the variable be used in the R scripts?
My code:
library(caret)
load("rpartModel.RData") #no way to run just once and be used as global?
predict(fitRPart,kyphosis[10,])

Found it.
Using the RBroker I can espcify a file to be preloaded, like in this java example https://github.com/deployr/java-example-fraud-score/blob/master/src/main/java/com/revo/deployr/rbroker/example/service/FraudService.java .
PoolPreloadOptions preloadOptions = new PoolPreloadOptions();
preloadOptions.filename = "rpartModel.rData";

Related

How to save a ranger model in mlr3 without data?

I have created a ranger model using mlr3 library. I saved this model to my machine using following command. The created file is huge in size. The saved file also has the data along with the model. Is there a way to only save the model without the data?
learner_ranger = lrn("classif.ranger", predict_type = "prob", predict_sets = c("train", "test"), importance = "impurity", num.threads = 8)
learner_ranger$train(train_task])
save(learner_ranger, file = "model.rda")
When I try to load this saved model it does not load the model correctly.
learner_ranger = load("model.rda")
str(learner_ranger)
Error in str(learner_ranger) : object 'learner_ranger' not found
To reduce the file size and save only the model, I have tried following but I am getting an error
save(learner_ranger$model, file = "model.rda")
The error I am getting is -
Error in save(learner_ranger$model, file = "model.rda") :
object ‘learner_randomF$model’ not found
After some research found that there are two ways to save and load the model in R:
using save(), load(): When we use save(), we will have to load it using the same name.
using saveRDS(), loadRDS(): saveRDS() does not save the model name and we have the flexibility to load the model in any other name. But saveRDS() can only save one object at a time as it is a lower-level function.
Most people prefer saveRDS() over save() as it serializes the object.
I am still looking for ways to save the model without data.

How to convert Tensorflow Object Detection API model to TFLite?

I am trying to convert a Tensorflow Object Detection model(ssd-mobilenet-v2-fpnlite, from TensorFlow 2 Detection Model Zoo) to TFLite. First of all, I train the model using the model_main_tf2.py and then I use the export_tflite_graph_tf2.py to export a saved model(.pb). However, when it comes to convert the .pb file to .tflite it throws this error:
OSError: SavedModel file does not exist at: /content/gdrive/My Drive/models/research/object_detection/fine_tuned_model/saved_model/saved_model.pb/{saved_model.pbtxt|saved_model.pb}
To convert the .pb file I used:
import tensorflow as tf
SAVED_MODEL_PATH = os.path.join(os.getcwd(),'object_detection', 'fine_tuned_model', 'saved_model', 'saved_model.pb')
# SAVED_MODEL_PATH: '/content/gdrive/My Drive/models/research/object_detection/exported_model/saved_model/saved_model.pb'
converter = tf.lite.TFLiteConverter.from_saved_model(SAVED_MODEL_PATH)
converter.optimizations = [tf.lite.Optimize.DEFAULT]
converter.experimental_new_converter = True
converter.target_spec.supported_ops = [tf.lite.OpsSet.TFLITE_BUILTINS, tf.lite.OpsSet.SELECT_TF_OPS]
tflite_model = converter.convert()
open("detect.tflite", "wb").write(tflite_model)
or "tflite_convert" from command line, but with the same error. I also tried to run it with the latest tf-nightly version as it suggests here, but the outcome is the same. I tried to pass the path with various ways, it seems like the .pd is not well written (not the right file). Is there a way to manage to convert the model to tflite so as to implement it to android? Thank you!
Your saved_model path should be "/content/gdrive/My Drive/models/research/object_detection/fine_tuned_model/saved_model/". It is the folder instead of files in that folder
For quick test, try to type in terminal
tflite_convert \
--saved_model_dir="path to saved_folder" \
--output_file="path to tflite file u want to save"
I don't have enough reputation to just comment but the problem here seems to be your SAVED_MODEL_PATH.
You could try to hardcode the path and remove the .pb file. I don't remember exactly what's the trick here but it's definitively due to the path

How to save a model when using MXnet

I am using MXnet for training a CNN (in R) and I can train the model without any error with the following code:
model <- mx.model.FeedForward.create(symbol=network,
X=train.iter,
ctx=mx.gpu(0),
num.round=20,
array.batch.size=batch.size,
learning.rate=0.1,
momentum=0.1,
eval.metric=mx.metric.accuracy,
wd=0.001,
batch.end.callback=mx.callback.log.speedometer(batch.size, frequency = 100)
)
But as this process is time-consuming, I run it on a server during the night and I want to save the model for the purpose of using it after finishing the training.
I used:
save(list = ls(), file="mymodel.RData")
and
mx.model.save("mymodel", 10)
But none of them can save the model! for example when I load the "mymodel.RData", I can not predict the labels for the test set!
Another example is when I load the "mymodel.RData" and try to plot it with the following code:
graph.viz(model$symbol$as.json())
I get the following error:
Error in model$symbol$as.json() : external pointer is not valid
Can anybody give me a solution for saving and then loading this model for future use?
Thanks
You can save the model by
model <- mx.model.FeedForward.create(symbol=network,
X=train.iter,
ctx=mx.gpu(0),
num.round=20,
array.batch.size=batch.size,
learning.rate=0.1,
momentum=0.1,
eval.metric=mx.metric.accuracy,
wd=0.001,
epoch.end.callback=mx.callback.save.checkpoint("model_prefix")
batch.end.callback=mx.callback.log.speedometer(batch.size, frequency = 100)
)
A mxnet model is an R list, but its first component is not an R object but a C++ pointer and can't be saved and reloaded as an R object. Therefore, the model needs to be serialized to behave as an actual R object. The serialized object is also a list, but its first object is a text string containing model information.
To save a model:
modelR <- mx.serialize(model)
save(modelR, file="~/model1.RData")
To retrieve it and use it again:
load("~/model1.RData", verbose=TRUE)
model <- mx.unserialize(modelR)
The best practice for saving a snapshot of your training progress is to use save_snapshot (http://mxnet.io/api/python/module.html#mxnet.module.Module.save_checkpoint) as part of the callback after every epoch training. In R the equivalent command is probably mx.callback.save.checkpoint, but I'm not using R and not sure about it usage.
Using these snapshots can also allow you to take advantage of the low cost option of using AWS Spot market (https://aws.amazon.com/ec2/spot/pricing/ ), which for example now offers and instance with 16 K80 GPUs for $3.8/hour compare to the on-demand price of $14.4. Such 80%-90% discount is common in the spot market and can optimize the speed and cost of your training, as long as you use these snapshots correctly.

An error while trying to use glm model for prediction on another computer

I would like to save a glm object in one R machine and use it for prediction on another data set located on another machine that has a newer data.I try to use save and load but with no success.What am I doing wrong?
Here is a toy example:
# on machine 1:
glm<-glm(y~x1+x2,data=dat1, family=binomial(link="logit")
save(glm,file="glm.Rdata") # the file is stored in a folder.
# on machine 2:
load(glm.RData) # got an error:"Error in load(glm.RData) : object 'glm.RData' not found"
#I tried :
load(file='glm.RData') # no error was displayed
print(glm) # got an error:"Error in load(glm.RData) : object 'glm.RData' not found"
Any help will be great.
As per #user3710546's advice, I would avoid saving your model using the name glm, as it'll mask (ie. block) the glm() function, making it difficult for you to use it in your session.
Using save() and load()
save() is generally used to save a list of objects to a file, rather than a single object. The first argument to save() is list, 'A character vector containing the names of objects to be saved.' (Emphasis mine.) So you'd want to use it like this:
# On machine 1:
save(list = 'glm', file = '/path/to/glm.RData')
# On machine 2:
load(file = '/path/to/glm.RData')
Note that the file extensions are often case-sensitive: you saved to a file with the extension .RData but loaded from one with the extension .Rdata, which is different. This may explain why the file isn't found.
Using saveRDS() and readRDS()
An alternative to using save() and load is to use saveRDS() and readRDS(), which are designed to be used with one object. They're used slightly differently:
# On machine 1
saveRDS(glm, file = '/path/to/glm.rds')
# On machine 2
glm = readRDS(file = '/path/to/glm.rds')
Note the .rds file extension and the fact that readRDS() isn't automatically put in the environment (it needs to be assigned to something).
Saving parts of a GLM
If you just want the formula saved—that is, the actual text string—you can find it in glm$formula, where glm is the name of your object. It comes back as a formula object, but you can convert it to a string with as.character(glm$formula), to then be written to a text file or whatever.
If, however, you want the model itself without the dataset it was created from (to cut down on disk space), have a look at this article, which discusses which parts of a glm object can be safely deleted.

import R forecast library JAR files into java

I am trying to import the R package 'forecast; in netbeans to use its functions. I have managed to make the JRI connection and also to import the javaGD library and experimented with it with a certain success. The problem about the forecasting package is that I cannot find the corresponding JAR files so to include them as a library in my project. I am loading it normally : re.eval(library(forecast)), but when I implement one of the library's function, a null value is returned. Although I am quite sure that the code is correct I am posting it just in case.
tnx in advance
Rengine re = new Rengine(Rargs, false, null);
System.out.println("rengine created, waiting for R!");
if(!re.waitForR())
{
System.out.println("cannot load R");
return;
}
re.eval("library(forecast)");
re.eval("library(tseries)");
re.eval("myData <- read.csv('C:/.../I-35E-NB_1.csv', header=F, dec='.', sep=',')");
System.out.println(re.eval("myData"));
re.eval("timeSeries <- ts(myData,start=1,frequency=24)");
System.out.println("this is time series object : " + re.eval("timeSeries"));
re.eval("fitModel <- auto.arima(timeSeries)");
REXP fc = re.eval("forecast(fitModel, n=20)");
System.out.println("this is the forecast output values: " + fc);
You did not convert values from R into java, you should first create a numerical vector of auto.arima output in R, and then use the method .asDoubleArray() to read it into java.
I gave a complete example in [here] How I can load add-on R libraries into JRI and execute from Java? , that shows exactly How to use the auto.arima function in Java using JRI.

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