Examples of Model Processes

GoLang Model Example

Here is an example of a GoLang model in VOR Stream. First, create the following testmod.strm and tables.csv files:

name testmod
type model
in input.csv -> input
node testmod(input)(output)
out output -> output.csv

tablename,varname,type,descr,arraylen,inherit,groupkey
input,,,Input table
input,num,num
output,,,Output table,,input
output,pd,num

Next, create input.csv file with a single field in the playpens input directory as follows:

num
1
1
2
2

Run vor create process testmod.strm and make the following edits to testmodU.go file:

1) add the following lines to the import list:

```go
    "frg.com/streamr/sdk"
    log "github.com/sirupsen/logrus"
```

2) add the following line to the User Struct

```go
    model     sdk.ModelS
```

3) add the following lines to the init block:

```go
    var err error
    u.model, err = frgutil.GetModelUnitTest(u.hh)
    log.Println("err is", err)
```

4) add the following lines to the worker function:

```go
    err := frgutil.RunModelUnitTest(u.model, input, u.Output)
    if err != nil {
        frgutil.EndJob(u.hh)
    }
    Output.Post(u.Output)
```

Now log into the UI, navigate to the Models tab and create a new Go model. Then add the following code to the Script section of the model definition:

package main

import (
    "log"
)

var output map[string]float64


func init() {
    output = make(map[string]float64)
}

func Model(input map[string]interface{}, args ...interface{}) (map[string]float64, error) {
    log.Printf("num %f\n", input["Num"])
    parms := map[string]float64{$parms$}

    output["Pd"] = parms["m"] * input["Num"].(float64) + parms["b"]

    return output, nil
}

Additionally, in the Parameters section of the model definition define two parameters b=1 and m=-2. Save the model, noting the Model ID in the top left corner of the screen.

Navigate back to your playpen and create the following joboptions.json file in the input directory, filling in the model ID you just created:

{
    "system": {
        "modelunittestid" : <model_ID>
    }
}

The set-up is now complete, and you are ready to run the model with vor run testmod.

Python Model Example

Here's an analogous example of a Python model. Create the following testmod.strm, tables.csv, and input.csv files:

name testmod
type model
in input.csv -> input 
node testmod(input)(output) lang=python
out output -> output.csv

input,,,Input table
input,num,num
output,,,Output table,,input
output,pd,num

num
1
1
2
2

Next, run vor create process testmod.strm and make the following edits to testmodU.py file:

1) add the following line to the import list:

```python
from sdk import framework
```

2) add the following lines to the init block:

```python
modelID = self.hh.options['JobOptions']['system']['modelunittestid']
self.model = framework.ReadModelByID(modelID)
```

3) add the following lines to the worker function:

```python
obs = input.__dict__
self.model.Model.model( obs , self.model.parms)
if len(self.model.output) > 0:
    self.Output.Post(Output.Output(**self.model.output))
```

Now log into the UI, navigate to the Models tab and create a new Python model. Add the following code to the Script section of the model definition:

import logging


class Model:
    output = dict()

    def __init__(self, output: dict()):
        self.output = output

    def model(self, input : dict(), parms : dict(), *argsv) :
        logging.info("In model " + str(parms))
        # copy to output for posting
        self.output["Num"] = input["Num"]

        self.output["Pd"] = parms["m"] * input["Num"] + parms["b"]

        return

Additionally, in the Parameters section of the model definition define two parameters b=1 and m=-2. Save the model, noting the Model ID in the top left corner of the screen.

Navigate back to your playpen and create the following joboptions.json file in the input directory, filling in the new model ID you just created:

{
    "system": {
        "modelunittestid" : <model_ID>
    }
}

The set-up is complete, and you are ready to run the model with vor run testmod.