ADM Explained¶
Pega
2023-03-15
This notebook shows exactly how all the values in an ADM model report are calculated. It also shows how the propensity is calculated for a particular customer.
We use one of the shipped datamart exports for the example. This is a model very similar to one used in some of the ADM PowerPoint/Excel deep dive examples. You can change this notebook to apply to your own data.
[2]:
import polars as pl
import numpy as np
import plotly.express as px
from math import log
from great_tables import GT
from pdstools import datasets
from pdstools.utils import cdh_utils
[3]:
model_name = "AutoNew84Months"
predictor_name = "Customer.NetWealth"
channel = "Web"
For the example we pick one particular model over a channel. To explain the ADM model report, we use one of the active predictors as an example. Swap for any other predictor when using different data.
[4]:
dm = datasets.cdh_sample()
model = dm.combined_data.filter(
(pl.col("Name") == model_name) & (pl.col("Channel") == channel)
)
modelpredictors = (
dm.combined_data.join(
model.select(pl.col("ModelID").unique()), on="ModelID", how="inner"
)
.filter(pl.col("EntryType") != "Inactive")
.with_columns(
Action=pl.concat_str(["Issue", "Group"], separator="/"),
PredictorName=pl.col("PredictorName").cast(pl.Utf8),
)
.collect()
)
predictorbinning = modelpredictors.filter(
pl.col("PredictorName") == predictor_name
).sort("BinIndex")
Model Overview¶
The selected model is shown below. Only the currently active predictors are used for the propensity calculation, so only showing those.
[6]:
Overview | |
Action | Sales/AutoLoans |
Channel | Web |
Name | AutoNew84Months |
Active Predictors | Classifier, Customer.Age, Customer.AnnualIncome, Customer.BusinessSegment, Customer.CLV, Customer.CLV_VALUE, Customer.CreditScore, Customer.Date_of_Birth, Customer.Gender, Customer.MaritalStatus, Customer.NetWealth, Customer.NoOfDependents, Customer.Prefix, Customer.RelationshipStartDate, Customer.RiskCode, Customer.WinScore, Customer.pyCountry, IH.Email.Outbound.Accepted.pxLastGroupID, IH.Email.Outbound.Accepted.pxLastOutcomeTime.DaysSince, IH.Email.Outbound.Accepted.pyHistoricalOutcomeCount, IH.Email.Outbound.Churned.pyHistoricalOutcomeCount, IH.Email.Outbound.Loyal.pxLastOutcomeTime.DaysSince, IH.Email.Outbound.Rejected.pyHistoricalOutcomeCount, IH.SMS.Outbound.Accepted.pxLastGroupID, IH.SMS.Outbound.Accepted.pyHistoricalOutcomeCount, IH.SMS.Outbound.Churned.pxLastOutcomeTime.DaysSince, IH.SMS.Outbound.Loyal.pxLastOutcomeTime.DaysSince, IH.SMS.Outbound.Loyal.pyHistoricalOutcomeCount, IH.SMS.Outbound.Rejected.pxLastGroupID, IH.SMS.Outbound.Rejected.pyHistoricalOutcomeCount, IH.Web.Inbound.Accepted.pxLastGroupID, IH.Web.Inbound.Accepted.pyHistoricalOutcomeCount, IH.Web.Inbound.Loyal.pxLastGroupID, IH.Web.Inbound.Loyal.pyHistoricalOutcomeCount, IH.Web.Inbound.Rejected.pxLastGroupID, IH.Web.Inbound.Rejected.pyHistoricalOutcomeCount, Param.ExtGroupCreditcards |
Model Performance (AUC) | 77.4901 |
Binning of the selected Predictor¶
The Model Report in Prediction Studio for this model will have a predictor binning plot like below.
All numbers can be derived from just the number of positives and negatives in each bin that are stored in the ADM Data Mart. The next sections will show exactly how that is done.
Predictor information | |
Predictor Name | Customer.NetWealth |
# Responses | 1636.0 |
# Bins | 8 |
Predictor Performance(AUC) | 72.2077 |
[8]:
Binning statistics | ||||||||
Range/Symbol | Responses (%) | Positives | Positives (%) | Negatives | Negatives (%) | Propensity (%) | ZRatio | Lift |
---|---|---|---|---|---|---|---|---|
<11684.56 | 26.70% | 13.0 | 6.30% | 423.0 | 29.60% | 2.98% | −11.19 | 0.24 |
[11684.56, 13732.56> | 12.30% | 24.0 | 11.70% | 178.0 | 12.40% | 11.88% | −0.33 | 0.94 |
[13732.56, 16845.52> | 16.30% | 17.0 | 8.30% | 250.0 | 17.50% | 6.37% | −4.26 | 0.51 |
[16845.52, 19139.28> | 14.10% | 51.0 | 24.80% | 179.0 | 12.50% | 22.17% | 3.91 | 1.76 |
[19139.28, 20286.16> | 5.50% | 7.0 | 3.40% | 83.0 | 5.80% | 7.78% | −1.71 | 0.62 |
[20286.16, 22743.76> | 13.60% | 53.0 | 25.70% | 169.0 | 11.80% | 23.87% | 4.40 | 1.90 |
[22743.76, 23890.64> | 5.50% | 13.0 | 6.30% | 77.0 | 5.40% | 14.44% | 0.52 | 1.15 |
>=23890.64 | 6.10% | 28.0 | 13.60% | 71.0 | 5.00% | 28.28% | 3.51 | 2.25 |
Total | 100.10% | 206.0 | 100.10% | 1430.0 | 100.00% | 117.77% | −5.16 | 9.35 |
Bin Statistics¶
Positive and Negative ratios¶
Internally, ADM only keeps track of the total counts of positive and negative responses in each bin. Everything else is derived from those numbers. The percentages and totals are trivially derived, and the propensity is just the number of positives divided by the total. The numbers calculated here match the numbers from the datamart table exactly.
[9]:
binning_derived = predictorbinning.select(
pl.col("BinSymbol").alias("Range/Symbol"),
BinPositives.alias("Positives"),
BinNegatives.alias("Negatives"),
((BinPositives + BinNegatives) / (sumPositives + sumNegatives)).alias(
"Responses %"
),
(BinPositives / sumPositives).alias("Positives %"),
(BinNegatives / sumNegatives).alias("Negatives %"),
(BinPositives / (BinPositives + BinNegatives)).round(4).alias("Propensity"),
)
pcts = ["Responses %", "Positives %", "Negatives %", "Propensity"]
GT(binning_derived).tab_header("Derived binning statistics").tab_style(
style=style.text(weight="bold"), locations=loc.body(columns="Range/Symbol")
).tab_style(
style=style.text(color="blue"),
locations=loc.body(columns=pcts),
).fmt_percent(pcts).tab_options(table_margin_left=0)
[9]:
Derived binning statistics | ||||||
Range/Symbol | Positives | Negatives | Responses % | Positives % | Negatives % | Propensity |
---|---|---|---|---|---|---|
<11684.56 | 13.0 | 423.0 | 26.65% | 6.31% | 29.58% | 2.98% |
[11684.56, 13732.56> | 24.0 | 178.0 | 12.35% | 11.65% | 12.45% | 11.88% |
[13732.56, 16845.52> | 17.0 | 250.0 | 16.32% | 8.25% | 17.48% | 6.37% |
[16845.52, 19139.28> | 51.0 | 179.0 | 14.06% | 24.76% | 12.52% | 22.17% |
[19139.28, 20286.16> | 7.0 | 83.0 | 5.50% | 3.40% | 5.80% | 7.78% |
[20286.16, 22743.76> | 53.0 | 169.0 | 13.57% | 25.73% | 11.82% | 23.87% |
[22743.76, 23890.64> | 13.0 | 77.0 | 5.50% | 6.31% | 5.38% | 14.44% |
>=23890.64 | 28.0 | 71.0 | 6.05% | 13.59% | 4.97% | 28.28% |
Lift¶
Lift is the ratio of the propensity in a particular bin over the average propensity. So a value of 1 is the average, larger than 1 means higher propensity, smaller means lower propensity:
[10]:
positives = pl.col("Positives")
negatives = pl.col("Negatives")
sumPositives = pl.sum("Positives")
sumNegatives = pl.sum("Negatives")
GT(
binning_derived.select(
"Range/Symbol",
"Positives",
"Negatives",
(
(positives / (positives + negatives))
/ (sumPositives / (positives + negatives).sum())
)
.round(4)
.alias("Lift"),
)
).tab_style(
style=style.text(weight="bold"), locations=loc.body(columns="Range/Symbol")
).tab_style(
style=style.text(color="blue"), locations=loc.body(columns=["Lift"])
).tab_options(table_margin_left=0)
[10]:
Range/Symbol | Positives | Negatives | Lift |
---|---|---|---|
<11684.56 | 13.0 | 423.0 | 0.2368 |
[11684.56, 13732.56> | 24.0 | 178.0 | 0.9436 |
[13732.56, 16845.52> | 17.0 | 250.0 | 0.5057 |
[16845.52, 19139.28> | 51.0 | 179.0 | 1.761 |
[19139.28, 20286.16> | 7.0 | 83.0 | 0.6177 |
[20286.16, 22743.76> | 53.0 | 169.0 | 1.896 |
[22743.76, 23890.64> | 13.0 | 77.0 | 1.1471 |
>=23890.64 | 28.0 | 71.0 | 2.2462 |
Z-Ratio¶
The Z-Ratio is also a measure of the how the propensity in a bin differs from the average, but takes into account the size of the bin and thus is statistically more relevant. It represents the number of standard deviations from the average, so centers around 0. The wider the spread, the better the predictor is.
See the calculation here, which is also included in cdh_utils’ zRatio().
[11]:
def z_ratio(
pos_col: pl.Expr = pl.col("BinPositives"), neg_col: pl.Expr = pl.col("BinNegatives")
) -> pl.Expr:
def get_fracs(pos_col=pl.col("BinPositives"), neg_col=pl.col("BinNegatives")):
return pos_col / pos_col.sum(), neg_col / neg_col.sum()
def z_ratio_impl(
pos_fraction_col=pl.col("posFraction"),
neg_fraction_col=pl.col("negFraction"),
positives_col=pl.sum("BinPositives"),
negatives_col=pl.sum("BinNegatives"),
):
return (
(pos_fraction_col - neg_fraction_col)
/ (
(pos_fraction_col * (1 - pos_fraction_col) / positives_col)
+ (neg_fraction_col * (1 - neg_fraction_col) / negatives_col)
).sqrt()
).alias("ZRatio")
return z_ratio_impl(*get_fracs(pos_col, neg_col), pos_col.sum(), neg_col.sum())
GT(
binning_derived.select(
"Range/Symbol", "Positives", "Negatives", "Positives %", "Negatives %"
).with_columns(z_ratio(positives, negatives).round(4))
).tab_style(
style=style.text(weight="bold"), locations=loc.body(columns="Range/Symbol")
).tab_style(
style=style.text(color="blue"), locations=loc.body(columns=["ZRatio"])
).fmt_percent(pl.selectors.ends_with("%")).tab_options(table_margin_left=0)
[11]:
Range/Symbol | Positives | Negatives | Positives % | Negatives % | ZRatio |
---|---|---|---|---|---|
<11684.56 | 13.0 | 423.0 | 6.31% | 29.58% | -11.1869 |
[11684.56, 13732.56> | 24.0 | 178.0 | 11.65% | 12.45% | -0.3321 |
[13732.56, 16845.52> | 17.0 | 250.0 | 8.25% | 17.48% | -4.2647 |
[16845.52, 19139.28> | 51.0 | 179.0 | 24.76% | 12.52% | 3.9082 |
[19139.28, 20286.16> | 7.0 | 83.0 | 3.40% | 5.80% | -1.7118 |
[20286.16, 22743.76> | 53.0 | 169.0 | 25.73% | 11.82% | 4.3976 |
[22743.76, 23890.64> | 13.0 | 77.0 | 6.31% | 5.38% | 0.5156 |
>=23890.64 | 28.0 | 71.0 | 13.59% | 4.97% | 3.5129 |
Predictor AUC¶
The predictor AUC is the univariate performance of this predictor against the outcome. This too can be derived from the positives and negatives and there is a convenient function in pdstools to calculate it directly from the positives and negatives.
This function is implemented in cdh_utils: cdh_utils.auc_from_bincounts().
[12]:
pos = binning_derived.get_column("Positives")
neg = binning_derived.get_column("Negatives")
probs = binning_derived.get_column("Propensity")
order = probs.arg_sort()
FPR = pl.Series([0.0]).extend(neg[order].cum_sum() / neg[order].sum())
TPR = pl.Series([0.0]).extend(pos[order].cum_sum() / pos[order].sum())
if TPR[1] < 1 - FPR[1]:
FPR, TPR = TPR, FPR
---------------------------------------------------------------------------
SchemaError Traceback (most recent call last)
Cell In[12], line 5
3 probs = binning_derived.get_column("Propensity")
4 order = probs.arg_sort()
----> 5 FPR = pl.Series([0.0]).extend(neg[order].cum_sum() / neg[order].sum())
6 TPR = pl.Series([0.0]).extend(pos[order].cum_sum() / pos[order].sum())
7 if TPR[1] < 1 - FPR[1]:
File ~/work/pega-datascientist-tools/pega-datascientist-tools/.venv/lib/python3.11/site-packages/polars/series/series.py:3005, in Series.extend(self, other)
2951 """
2952 Extend the memory backed by this Series with the values from another.
2953
(...)
3002 1
3003 """
3004 try:
-> 3005 self._s.extend(other._s)
3006 except RuntimeError as exc:
3007 if str(exc) == "Already mutably borrowed":
SchemaError: type Float32 is incompatible with expected type Float64
[13]:
pos = binning_derived.get_column("Positives").to_numpy()
neg = binning_derived.get_column("Negatives").to_numpy()
probs = binning_derived.get_column("Propensity").to_numpy()
order = np.argsort(probs)
FPR = np.cumsum(neg[order]) / np.sum(neg[order])
TPR = np.cumsum(pos[order]) / np.sum(pos[order])
TPR = np.insert(TPR, 0, 0, axis=0)
FPR = np.insert(FPR, 0, 0, axis=0)
# Checking whether classifier labels are correct
if TPR[1] < 1 - FPR[1]:
temp = FPR
FPR = TPR
TPR = temp
auc = cdh_utils.auc_from_bincounts(pos=pos, neg=neg, probs=probs)
fig = px.line(
x=[1 - x for x in FPR],
y=TPR,
labels=dict(x="Specificity", y="Sensitivity"),
title=f"AUC = {auc.round(3)}",
width=700,
height=700,
range_x=[1, 0],
template="none",
)
fig.add_shape(type="line", line=dict(dash="dash"), x0=1, x1=0, y0=0, y1=1)
fig.show()
Naive Bayes and Log Odds¶
The basis for the Naive Bayes algorithm is Bayes’ Theorem:
with \(C_k\) the outcome and \(x\) the customer. Bayes’ theorem turns the question “what’s the probability to accept this action given a customer” around to “what’s the probability of this customer given an action”. With the independence assumption, and after applying a log odds transformation we get a log odds score that can be calculated efficiently and in a numerically stable manner:
note that the prior can be written as:
Predictor Contribution¶
The contribution (conditional log odds) of an active predictor \(p\) for bin \(i\) with the number of positive and negative responses in \(Positives_i\) and \(Negatives_i\) is calculated as (note the “laplace smoothing” to avoid log 0 issues):
[14]:
N = binning_derived.shape[0]
GT(
binning_derived.with_columns(
LogOdds=(pl.col("Positives %") / pl.col("Negatives %")).log().round(5),
ModifiedLogOdds=(
((positives + 1 / N).log() - (positives.sum() + 1).log())
- ((negatives + 1 / N).log() - (negatives.sum() + 1).log())
).round(5),
).drop("Responses %", "Propensity")
).tab_style(
style=style.text(weight="bold"), locations=loc.body(columns="Range/Symbol")
).tab_style(
style=style.text(color="blue"),
locations=loc.body(columns=["LogOdds", "ModifiedLogOdds"]),
).fmt_percent(pl.selectors.ends_with("%")).tab_options(table_margin_left=0)
[14]:
Range/Symbol | Positives | Negatives | Positives % | Negatives % | LogOdds | ModifiedLogOdds |
---|---|---|---|---|---|---|
<11684.56 | 13.0 | 423.0 | 6.31% | 29.58% | -1.54487 | -1.53974 |
[11684.56, 13732.56> | 24.0 | 178.0 | 11.65% | 12.45% | -0.06618 | -0.06583 |
[13732.56, 16845.52> | 17.0 | 250.0 | 8.25% | 17.48% | -0.75069 | -0.74801 |
[16845.52, 19139.28> | 51.0 | 179.0 | 24.76% | 12.52% | 0.68199 | 0.6796 |
[19139.28, 20286.16> | 7.0 | 83.0 | 3.40% | 5.80% | -0.53538 | -0.52333 |
[20286.16, 22743.76> | 53.0 | 169.0 | 25.73% | 11.82% | 0.77795 | 0.77542 |
[22743.76, 23890.64> | 13.0 | 77.0 | 6.31% | 5.38% | 0.1587 | 0.1625 |
>=23890.64 | 28.0 | 71.0 | 13.59% | 4.97% | 1.00708 | 1.00563 |
Propensity mapping¶
Log odds contribution for all the predictors¶
The final score is loosely referred to as “the average contribution” but in fact is a little more nuanced. The final score is calculated as:
Here, \(TotalPositives\) and \(TotalNegatives\) are the total number of positive and negative responses to the model.
Below an example. From all the active predictors of the model we pick a value (in the middle for numerics, first symbol for symbolics) and show the (modified) log odds. The final score is calculated per the above formula, and this is the value that is mapped to a propensity value by the classifier (which is constructed using the PAV(A) algorithm).
[15]:
PredictorName | Value | Bin | Positives | Negatives | LogOdds |
---|---|---|---|---|---|
Customer.Age | 34.56 | 4 | 9.0 | 198.0 | -1.1459 |
Customer.AnnualIncome | -24043.049 | 1 | 74.0 | 1166.0 | -0.8197 |
Customer.BusinessSegment | middleSegmentPlus | 1 | 96.0 | 970.0 | -0.3764 |
Customer.CLV | NON-MISSING | 1 | 111.0 | 570.0 | 0.3009 |
Customer.CLV_VALUE | 1345.52 | 4 | 31.0 | 297.0 | -0.3227 |
Customer.CreditScore | 518.92 | 3 | 33.0 | 205.0 | 0.1105 |
Customer.Date_of_Birth | 18773.504 | 5 | 28.0 | 152.0 | 0.2446 |
Customer.Gender | U | 1 | 52.0 | 481.0 | -0.2855 |
Customer.MaritalStatus | No Resp+ | 1 | 67.0 | 745.0 | -0.4708 |
Customer.NetWealth | 17992.398 | 4 | 51.0 | 179.0 | 0.6796 |
Customer.NoOfDependents | 0.0 | 1 | 111.0 | 850.0 | -0.0997 |
Customer.Prefix | Mrs. | 1 | 64.0 | 552.0 | -0.2167 |
Customer.RelationshipStartDate | 1426.4596 | 4 | 16.0 | 117.0 | -0.0502 |
Customer.RiskCode | R4 | 1 | 36.0 | 329.0 | -0.2709 |
Customer.WinScore | 66.600006 | 4 | 39.0 | 102.0 | 0.9738 |
Customer.pyCountry | USA | 1 | 99.0 | 776.0 | -0.1227 |
IH.Email.Outbound.Accepted.pxLastGroupID | HomeLoans | 3 | 25.0 | 218.0 | -0.2272 |
IH.Email.Outbound.Accepted.pxLastOutcomeTime.DaysSince | -55.88436 | 2 | 145.0 | 881.0 | 0.1305 |
IH.Email.Outbound.Accepted.pyHistoricalOutcomeCount | 1.5 | 2 | 30.0 | 351.0 | -0.5201 |
IH.Email.Outbound.Churned.pyHistoricalOutcomeCount | None | 1 | 143.0 | 898.0 | 0.1015 |
IH.Email.Outbound.Loyal.pxLastOutcomeTime.DaysSince | None | 1 | 129.0 | 1071.0 | -0.1788 |
IH.Email.Outbound.Rejected.pyHistoricalOutcomeCount | 83.16 | 3 | 24.0 | 218.0 | -0.2678 |
IH.SMS.Outbound.Accepted.pxLastGroupID | Account | 4 | 45.0 | 316.0 | -0.0133 |
IH.SMS.Outbound.Accepted.pyHistoricalOutcomeCount | 9.02 | 4 | 6.0 | 96.0 | -0.822 |
IH.SMS.Outbound.Churned.pxLastOutcomeTime.DaysSince | -20.5537 | 2 | 9.0 | 27.0 | 0.8492 |
IH.SMS.Outbound.Loyal.pxLastOutcomeTime.DaysSince | None | 1 | 165.0 | 1240.0 | -0.0797 |
IH.SMS.Outbound.Loyal.pyHistoricalOutcomeCount | None | 1 | 165.0 | 1240.0 | -0.0797 |
IH.SMS.Outbound.Rejected.pxLastGroupID | Account | 2 | 47.0 | 357.0 | -0.0905 |
IH.SMS.Outbound.Rejected.pyHistoricalOutcomeCount | 102.72 | 4 | 12.0 | 117.0 | -0.3356 |
IH.Web.Inbound.Accepted.pxLastGroupID | DepositAccounts | 3 | 53.0 | 397.0 | -0.0779 |
IH.Web.Inbound.Accepted.pyHistoricalOutcomeCount | 11.04 | 5 | 25.0 | 164.0 | 0.0558 |
IH.Web.Inbound.Loyal.pxLastGroupID | MISSING | 1 | 100.0 | 857.0 | -0.2119 |
IH.Web.Inbound.Loyal.pyHistoricalOutcomeCount | 4.52 | 3 | 30.0 | 212.0 | -0.0172 |
IH.Web.Inbound.Rejected.pxLastGroupID | Account | 2 | 81.0 | 546.0 | 0.0279 |
IH.Web.Inbound.Rejected.pyHistoricalOutcomeCount | 111.08 | 4 | 35.0 | 306.0 | -0.2317 |
Param.ExtGroupCreditcards | NON-MISSING | 1 | 136.0 | 721.0 | 0.2684 |
Final Score | None | None | None | None | -0.14933270233219137 |
Classifier¶
The success rate is defined as \(\frac{positives}{positives+negatives}\) per bin.
The adjusted propensity that is returned is a small modification (Laplace smoothing) to this and calculated as \(\frac{0.5+positives}{1+positives+negatives}\) so empty models return a propensity of 0.5.
[16]:
Index | Bin | Positives | Negatives | Cum. Total (%) | Propensity (%) | Adjusted Propensity (%) | Cum Positives (%) | ZRatio | Lift(%) |
---|---|---|---|---|---|---|---|---|---|
1 | <-0.21 | 17.0 | 443.0 | 28.12% | 3.70% | 3.80% | 8.25% | -9.9945 | 1.96% |
2 | [-0.21, -0.185> | 8.0 | 133.0 | 36.74% | 5.67% | 5.99% | 12.14% | -3.4954 | 3.00% |
3 | [-0.185, -0.175> | 3.0 | 48.0 | 39.85% | 5.88% | 6.73% | 13.59% | -1.9775 | 3.11% |
4 | [-0.175, -0.105> | 28.0 | 370.0 | 64.18% | 7.04% | 7.14% | 27.18% | -4.6281 | 3.72% |
5 | [-0.105, -0.095> | 4.0 | 51.0 | 67.54% | 7.27% | 8.04% | 29.13% | -1.5054 | 3.85% |
6 | [-0.095, -0.09> | 2.0 | 19.0 | 68.83% | 9.52% | 11.36% | 30.10% | -0.4788 | 5.04% |
7 | [-0.09, -0.065> | 9.0 | 77.0 | 74.08% | 10.47% | 10.92% | 34.47% | -0.6578 | 5.54% |
8 | [-0.065, -0.02> | 30.0 | 154.0 | 85.33% | 16.30% | 16.49% | 49.03% | 1.4644 | 8.63% |
9 | [-0.02, 0.03> | 37.0 | 65.0 | 91.56% | 36.27% | 36.41% | 66.99% | 4.913 | 19.21% |
10 | [0.03, 0.06> | 20.0 | 29.0 | 94.56% | 40.82% | 41.00% | 76.70% | 3.664 | 21.61% |
11 | [0.06, 0.12> | 30.0 | 33.0 | 98.41% | 47.62% | 47.66% | 91.26% | 4.9229 | 25.21% |
12 | [0.12, 0.125> | 2.0 | 2.0 | 98.66% | 50.00% | 50.00% | 92.23% | 1.2039 | 26.47% |
13 | [0.125, 0.13> | 4.0 | 2.0 | 99.02% | 66.67% | 64.29% | 94.17% | 1.8644 | 35.30% |
14 | [0.13, 0.995> | 8.0 | 3.0 | 99.69% | 72.73% | 70.83% | 98.06% | 2.7182 | 38.51% |
15 | >=0.995 | 4.0 | 1.0 | 100.00% | 80.00% | 75.00% | 100.00% | 1.9418 | 42.36% |
Final Propensity¶
Below the classifier mapping. On the x-axis the binned scores (log odds values), on the y-axis the Propensity. Note the returned propensities are following a slightly adjusted formula, see the table above. The bin that contains the calculated final score is highlighted.
[17]:
score = propensity_mapping.filter(PredictorName="Final Score")["LogOdds"][0]
score_bin = (
modelpredictors.filter(pl.col("EntryType") == "Classifier")
.select(
pl.col("BinSymbol").filter(
pl.lit(score).is_between(pl.col("BinLowerBound"), pl.col("BinUpperBound"))
)
)
.item()
)
score_responses = modelpredictors.filter(
(pl.col("EntryType") == "Classifier") & (pl.col("BinSymbol") == score_bin)
)["BinResponseCount"][0]
score_bin_index = (
modelpredictors.filter(pl.col("EntryType") == "Classifier")["BinSymbol"]
.to_list()
.index(score_bin)
)
score_propensity = classifier.row(score_bin_index, named=True)[
"Adjusted Propensity (%)"
]
adjusted_propensity = (
modelpredictors.filter(pl.col("EntryType") == "Classifier")
.with_columns(
AdjustedPropensity=(
(0.5 + BinPositives) / (1 + BinPositives + BinNegatives)
).round(5),
)
.select(
pl.col("AdjustedPropensity").filter(
(pl.col("BinLowerBound") < score) & (pl.col("BinUpperBound") > score)
)
)["AdjustedPropensity"][0]
)
fig = dm.plot.score_distribution(
model_id=modelpredictors.get_column("ModelID").unique().to_list()[0]
).add_annotation(
x=score_bin,
y=score_propensity / 100,
text=f"Returned propensity: {score_propensity*100:.2f}%",
bgcolor="#FFFFFF",
bordercolor="#000000",
showarrow=False,
yref="y2",
opacity=0.7,
)
bin_index = list(fig.data[0]["x"]).index(score_bin)
fig.data[0]["marker_color"] = (
["grey"] * bin_index
+ ["#1f77b4"]
+ ["grey"] * (classifier.shape[0] - bin_index - 1)
)
fig
[ ]: