fetchSM: Fetches student model from database or JSON

In ralmond/EABN: Evidence Accumulation Bayes Net Engine

Fetches student model from database or JSON

Description

The function fetchSM retrieves the student model from a PnetWarehouse or if not there, attempts to recreate it from a serialized version. The function unpackSM does this unpacking.

Usage

fetchSM(sr, warehouse)
unpackSM(sr, warehouse)

Arguments

sr	An object of class StudentRecord whose student model we wish to retrieve.
warehouse	A PnetWarehouse which stores the student models.

Details

The StudentRecord object has two fields related to student models: sm and smser. The former contains the actual student model or NULL if it has not yet been initialized or restored from the database. The latter contains a character string which contains a serialized version of the student model. In particular, it is this serialized student model which is stored in the database, not the actual student model.

The function fetchSM is used to set the sm field. It checks the following places in order:

1. It looks in the warehouse for a student net for the given uid for the record.

2. It calls unpackSM to unpack the serialized record.

The function unpackSM is wrapper for the function WarehouseUnpack.

Value

The function fetchSM returns the modified StudentRecord.

The function unpackSM returns the student model (a Pnet).

Author(s)

Russell Almond

See Also

StudentRecord

PnetWarehouse, WarehouseUnpack

Examples

library(PNetica)

##Start with manifest
sess <- RNetica::NeticaSession()
RNetica::startSession(sess)

## BNWarehouse is the PNetica Net Warehouse.
## This provides an example network manifest.
config.dir <- file.path(library(help="Peanut")$path, "auxdata")
netman1 <- read.csv(file.path(config.dir,"Mini-PP-Nets.csv"),
                    row.names=1, stringsAsFactors=FALSE)
net.dir <- file.path(library(help="PNetica")$path, "testnets")
Nethouse <- PNetica::BNWarehouse(manifest=netman1,session=sess,key="Name",
                       address=net.dir)

dsr <- StudentRecord("*DEFAULT*",app="ecd://epls.coe.fsu.edu/P4Test",
                     context="*Baseline*")
sm(dsr) <- WarehouseSupply(Nethouse,"miniPP_CM")
PnetCompile(sm(dsr))

## dsr <- updateStats(eng,dsr)
statmat <- read.csv(file.path(config.dir,"Mini-PP-Statistics.csv"),
                    stringsAsFactors=FALSE)
rownames(statmat) <- statmat$Name
statlist <- sapply(statmat$Name,function (st)
    Statistic(statmat[st,"Fun"],statmat[st,"Node"],st))
names(statlist) <- statmat$Name 
dsr@stats <- lapply(statlist,
                    function (stat) calcStat(stat,sm(dsr)))
names(dsr@stats) <- names(statlist)

## dsr <- baselineHist(eng,dsr)
dsr@hist <- lapply(c("Physics"),
                     function (nd)
                     EABN:::uphist(sm(dsr),nd,NULL,"*Baseline*"))
names(dsr@hist) <- "Physics"

pnodenames <- names(PnetPnodes(sm(dsr)))


## Serialization and unserialization
dsr.ser <- as.json(dsr)

dsr1 <- parseStudentRecord(jsonlite::fromJSON(dsr.ser))
stopifnot(is.null(sm(dsr1)))
## at this point, SM has not yet been restored.


## It is there in the serial field
net1 <- unpackSM(dsr1,Nethouse)
stopifnot(all.equal(pnodenames,names(PnetPnodes(net1))))
dsr1 <- fetchSM(dsr1,Nethouse)
stopifnot(all.equal(pnodenames,names(PnetPnodes(sm(dsr1)))))

## Try this again, but first delete net from warehouse,
## So we are sure we are building it from serialized version.
WarehouseFree(Nethouse,PnetName(sm(dsr)))

dsr1 <- parseStudentRecord(jsonlite::fromJSON(dsr.ser))
stopifnot(is.null(sm(dsr1)))
## at this point, SM has not yet been restored.


## It is there in the serial field
net1 <- unpackSM(dsr1,Nethouse)
stopifnot(all.equal(pnodenames,names(PnetPnodes(net1))))
dsr1 <- fetchSM(dsr1,Nethouse)
stopifnot(all.equal(pnodenames,names(PnetPnodes(sm(dsr1)))))

ralmond/EABN documentation built on Aug. 30, 2023, 12:52 p.m.