dharmatech

Generics in Scheme

In a previous note I demonstrated polymorphism in Scheme using Chez Scheme's compile time values and properties.

The code in that example is pretty raw; you might not want to code each generic in that manner. One approach is to decouple the signature/method table. We can do this by factoring out some code into a 'make-generic' procedure:

(define (make-generic table)
  (lambda (stx)
 (lambda (lookup)

dharmatech

# https://www.ffiec.gov/npw/FinancialReport/FinancialDataDownload

# $result_bhcf = Import-Csv .\BHCF.csv

# $result_rssd = Import-Csv .\RSSD.csv

Write-Host 'Importing CSV...' -ForegroundColor Yellow -NoNewline

# $result = Import-Csv -Delimiter '^' -Path BHCF20221231.txt

dharmatech

Polymorphism in Scheme via compile time dispatch

Here's an example of polymorphism in C++:

int nth ( int a[] , int i ) { return a[i] ; }

double nth ( double a[] , int i ) { return a[i] ; }

One way to think of this is that there are two functions called nth. One can be called with an int array and the other can be called with a double array. The function that is called is determined at compile time by looking at the type of the expression of the first argument.

dharmatech

import pandas as pd
import treasury_gov_pandas
from bokeh.plotting import figure, show
from bokeh.models   import NumeralTickFormatter, HoverTool
import bokeh.models

import bokeh.palettes
import bokeh.transform
# ----------------------------------------------------------------------
# df = treasury_gov_pandas.update_records(

dharmatech

import numpy as np
import pandas as pd
import treasury_gov_pandas

df = treasury_gov_pandas.update_records('https://api.fiscaldata.treasury.gov/services/api/fiscal_service/v1/accounting/od/auctions_query')

# print(df.iloc[0].to_string())

# print(df.iloc[-10].to_string())

dharmatech

Let's solve the following physics problem using Symbolism, a computer algebra library for C#.

One strategy in a snowball fight is to throw a first snowball at a high angle over level ground. While your opponent is watching the first one, you throw a second one at a low angle and timed to arrive at your opponent before or at the same time as the first one.

Assume both snowballs are thrown with a speed of 25.0 m/s.

The first one is thrown at an angle of 70.0° with respect to the horizontal.

dharmatech

import pandas as pd

from bokeh.plotting import figure, show
from bokeh.models   import NumeralTickFormatter, HoverTool

from bokeh.models import LinearAxis, Range1d

import yfinance as yf

import treasury_gov_pandas

dharmatech

import pandas as pd
import treasury_gov_pandas

from bokeh.plotting import figure, show
from bokeh.models   import NumeralTickFormatter, HoverTool
# ---------------------------------------------------------------------
df = treasury_gov_pandas.update_records(
    'auctions_query.pkl',
    'https://api.fiscaldata.treasury.gov/services/api/fiscal_service/v1/accounting/od/auctions_query')
# ----------------------------------------------------------------------

dharmatech

import pandas as pd
import treasury_gov_pandas
from bokeh.plotting import figure, show
from bokeh.models   import NumeralTickFormatter, HoverTool
import bokeh.models

import bokeh.palettes
import bokeh.transform
# ----------------------------------------------------------------------
df = treasury_gov_pandas.update_records(

dharmatech

import pandas as pd

from bokeh.plotting import figure, show
from bokeh.models   import NumeralTickFormatter, HoverTool

from bokeh.models import LinearAxis, Range1d

import yfinance as yf
# ---------------------------------------------------------------------
df = treasury_gov_pandas.update_records(