Give rules as true/false rather than strings [#20]

- Rule columns prefixed with 'rules_'
- Data columns prefixed with 'data_'
- ID columns prefixed with 'id_'

Also removed some superfluous calculations.

Author: jchester

README.md

@@ -240,26 +240,31 @@ Each row in a Rule view tells you whether a Sample was within control limits, or
 Let's look at Table 6.2 and see if we can find out-of-control Samples:
 
 ```sql
-select sample_id,
-       controlled_value,
-       upper_limit,
-       control_status
+select id_sample                    as "Sample ID",
+       data_controlled_value        as "Sample Average",
+       data_upper_limit             as "Upper Limit",
+       rule_in_control              as "In Control?",
+       rule_out_of_control_upper    as "Out of Control Upper?"
 from spc_reports.x_bar_r_rules
-where control_window_id = 2
-  and control_status != 'in_control'
-order by sample_id;
+where id_control_window = 2
+  and not rule_in_control
+order by id_sample;
 ```
 
 Giving:
 
-| Sample ID | Sample Average | Upper Limit | Control Status |
-|-----------|----------------|-------------|----------------|
-| 43 | 1.69696 | 1.693224336 | out_of_control_upper |
-| 45 | 1.77 | 1.693224336 | out_of_control_upper |
+| Sample ID | Sample Average | Upper Limit | In Control? | Out of Control Upper? |
+|-----------|----------------|-------------|-------------|-----------------------|
+| 43        | 1.69696        | 1.693224336 | false       | true                  |
+| 45        | 1.77           | 1.693224336 | false       | true                  |
 
-We can see that samples 43 and 45 are unusually high: they are `out_of_control_upper`. This means we need to perform an
+We can see that samples 43 and 45 are unusually high: they are out of control. This means we need to perform an
 investigation to establish what has occurred to cause the unusual sample average.
 
+You may have noticed the prefixes for each column. They follow a consistent pattern across different views and
+functions: `id_` refers to an ID from another table, `data_` represents some value as of that sample and `rule_` is
+whether a particular rule has been matched or not.
+
 ## References and Further Reading
 
 Listed in suggested order of priority.

spec/montgomery_spec.rb

@@ -13,11 +13,11 @@ class MontgomerySpec < SpcSpec
   end
 
   describe "Flow Width example" do
-    instrument_id = 1
+    id_instrument = 1
 
     describe "x̄R rules" do
       subject do
-        DB[:x_bar_r_rules].where(instrument_id:)
+        DB[:x_bar_r_rules].where(id_instrument:)
       end
 
       it_has_params(mean: 1.506, upper: 1.693, lower: 1.318)
@@ -29,7 +29,7 @@ class MontgomerySpec < SpcSpec
 
     describe "R̄ rules" do
       subject do
-        DB[:r_rules].where(instrument_id:)
+        DB[:r_rules].where(id_instrument:)
       end
 
       it_has_params(mean: 0.32521, upper: 0.68749, lower: 0)
@@ -39,11 +39,11 @@ class MontgomerySpec < SpcSpec
   end
 
   describe "Engine Piston Diameter example" do
-    instrument_id = 2
+    id_instrument = 2
 
     describe "x̄s rules" do
       subject do
-        DB[:x_bar_s_rules].where(instrument_id:)
+        DB[:x_bar_s_rules].where(id_instrument:)
       end
 
       it_has_params(mean: 74.001, upper: 74.014, lower: 73.988)
@@ -53,7 +53,7 @@ class MontgomerySpec < SpcSpec
 
     describe "s̄ rules" do
       subject do
-        DB[:s_rules].where(instrument_id:)
+        DB[:s_rules].where(id_instrument:)
       end
 
       it_has_params(mean: 0.0094, upper: 0.0196, lower: 0)
@@ -63,11 +63,11 @@ class MontgomerySpec < SpcSpec
   end
 
   describe "Orange Juice Can Inspection" do
-    instrument_id = 3
+    id_instrument = 3
 
     describe "p non-conformant rules" do
       subject do
-        DB[:p_non_conformant_rules].where(instrument_id:)
+        DB[:p_non_conformant_rules].where(id_instrument:)
       end
 
       it_has_params(mean: 0.2313, upper: 0.4102, lower: 0.0524)
@@ -79,7 +79,7 @@ class MontgomerySpec < SpcSpec
 
     describe "np non-conformant rules" do
       subject do
-        DB[:np_non_conformant_rules].where(instrument_id:)
+        DB[:np_non_conformant_rules].where(id_instrument:)
       end
 
       it_has_params(mean: 11.565, upper: 20.510, lower: 2.620)
@@ -91,11 +91,11 @@ class MontgomerySpec < SpcSpec
   end
 
   describe "Printed Circuit Boards" do
-    instrument_id = 4
+    id_instrument = 4
 
     describe "c rules" do
       subject do
-        DB[:c_rules].where(instrument_id:)
+        DB[:c_rules].where(id_instrument:)
       end
 
       it_has_params(mean: 19.85, upper: 33.22, lower: 6.48)
@@ -107,11 +107,11 @@ class MontgomerySpec < SpcSpec
   end
 
   describe "Mortgage Loan Cost" do
-    instrument_id = 5
+    id_instrument = 5
 
     describe "XmR X rules" do
       subject do
-        DB[:xmr_x_rules].where(instrument_id:)
+        DB[:xmr_x_rules].where(id_instrument:)
       end
 
       it_has_params(mean: 300.5, upper: 321.22, lower: 279.78)
@@ -123,19 +123,19 @@ class MontgomerySpec < SpcSpec
 
     describe "XmR MR rules" do
       subject do
-        DB[:xmr_mr_rules].where(instrument_id:)
+        DB[:xmr_mr_rules].where(id_instrument:)
       end
 
       it_has_params(mean: 7.79, upper: 25.45, lower: 0)
 
-      it_has_status_counts_of(in_control: 39, out_of_control_upper: 1, out_of_control_lower: 0)
+      it_has_status_counts_of(in_control: 38, out_of_control_upper: 1, out_of_control_lower: 0)
 
       it_is_out_of_control_at(upper_samples: [165], lower_samples: [])
     end
   end
 
   describe "Normal Distribution With Shifting Mean" do
-    instrument_id = 6
+    id_instrument = 6
 
     describe "EWMA with fixed targets" do
       subject do
@@ -146,7 +146,7 @@ class MontgomerySpec < SpcSpec
                      10, # target mean
                      1 # target std dev
           )
-        ).where(instrument_id:).order_by(:sample_id)
+        ).where(id_instrument:).order_by(:id_sample)
       end
 
       it_has_params(mean: 10, upper: 10.27, lower: 9.73)
@@ -156,7 +156,7 @@ class MontgomerySpec < SpcSpec
       it_is_out_of_control_at(upper_samples: [195, 196], lower_samples: [])
 
       # @formatter:off
-      it_has_correct_values(column: :exponentially_weighted_moving_average, values: [
+      it_has_correct_values(column: :data_exponentially_weighted_moving_average, values: [
         9.945,    9.7495, 9.70355,  9.8992, 10.1253, 10.1307, 9.92167, 10.0755, 9.98796, 10.0232,
         9.92384, 10.0785, 10.1216, 10.0495, 10.0525, 9.98426, 10.0478,  10.074, 9.91864, 10.0108,
         10.0997, 10.0227, 10.2495, 10.3745, 10.3971, 10.4654, 10.4568, 10.5731, 10.6468, 10.6341
@@ -171,15 +171,15 @@ class MontgomerySpec < SpcSpec
                      0.1, # weighting
                      2.7 # limits
           )
-        ).where(instrument_id:).order_by(:sample_id)
+        ).where(id_instrument:).order_by(:id_sample)
       end
 
       it_has_params(mean: 10.315, upper: 10.626, lower: 10.004)
 
       it_has_status_counts_of(in_control: 30, out_of_control_upper: 0, out_of_control_lower: 0)
 
       # @formatter:off
-      it_has_correct_values(column: :exponentially_weighted_moving_average, values: [
+      it_has_correct_values(column: :data_exponentially_weighted_moving_average, values: [
         10.2285, 10.0046, 9.93318, 10.1058, 10.3112, 10.2981, 10.0723, 10.2111, 10.1099, 10.1329,
         10.0226, 10.1674, 10.2016, 10.1215, 10.1173, 10.0426, 10.1003, 10.1213, 9.96119, 10.0490,
         10.1341, 10.0537, 10.2773, 10.3996, 10.4196, 10.4857, 10.4751, 10.5896, 10.6616, 10.6474
@@ -195,11 +195,11 @@ class MontgomerySpec < SpcSpec
                      5, # decision interval
                      10 # target mean
           )
-        ).where(instrument_id:).order_by(:sample_id)
+        ).where(id_instrument:).order_by(:id_sample)
       end
 
       describe "Calculating net deviation" do
-        it_has_correct_values(column: :deviation, values: [
+        it_has_correct_values(column: :data_deviation, values: [
           # @formatter:off
           -0.55,  -2.01,  -0.71,  1.66,   2.16,
           0.18,   -1.96,  1.46,   -0.8,   0.34,
@@ -212,7 +212,7 @@ class MontgomerySpec < SpcSpec
       end
 
       describe "Calculating Cₙ" do
-        it_has_correct_values(column: :c_n, values: [
+        it_has_correct_values(column: :data_c_n, values: [
           # @formatter:off
           -0.55,  -2.56,  -3.27,  -1.61,  0.55,
           0.73,   -1.23,  0.23,   -0.57,  -0.23,
@@ -225,7 +225,7 @@ class MontgomerySpec < SpcSpec
       end
 
       describe "Calculating positive deviation" do
-        it_has_correct_values(column: :deviation_plus, values: [
+        it_has_correct_values(column: :data_deviation_plus, values: [
           # @formatter:off
           -1.05,  -2.51,  -1.21,  1.16,   1.66,
           -0.32,  -2.46,  0.96,   -1.3,   -0.16,
@@ -238,7 +238,7 @@ class MontgomerySpec < SpcSpec
       end
 
       describe "Calculating C⁺" do
-        it_has_correct_values(column: :c_plus, values: [
+        it_has_correct_values(column: :data_c_plus, values: [
           # @formatter:off
           0,      0,      0,      1.16,   2.82,
           2.50,   0.04,   1.00,   0,      0,
@@ -251,7 +251,7 @@ class MontgomerySpec < SpcSpec
       end
 
       describe "Calculating negative deviation" do
-        it_has_correct_values(column: :deviation_minus, values: [
+        it_has_correct_values(column: :data_deviation_minus, values: [
           # @formatter:off
           -0.05,  -1.51,  -0.21,  2.16,   2.66,
           0.68,   -1.46,  1.96,   -0.3,   0.84,
@@ -264,7 +264,7 @@ class MontgomerySpec < SpcSpec
       end
 
       describe "Calculating C⁻" do
-        it_has_correct_values(column: :c_minus, values: [
+        it_has_correct_values(column: :data_c_minus, values: [
           # @formatter:off
           -0.05,  -1.56,    -1.77,  0,      0,
           0,      -1.46,    0,      -0.3,   0,

spec/spc_spec.rb

@@ -19,46 +19,46 @@ def run(*args, &block)
 
   def self.it_has_params(mean:, upper:, lower:)
     it "has the correct mean" do
-      assert_in_delta mean, subject.first[:center_line], 0.01
+      assert_in_delta mean, subject.first[:data_center_line], 0.01
     end
 
     it "has the correct upper limit" do
-      assert_in_delta upper, subject.first[:upper_limit], 0.01
+      assert_in_delta upper, subject.first[:data_upper_limit], 0.01
     end
 
     it "has the correct lower limit" do
-      assert_in_delta lower, subject.first[:lower_limit], 0.01
+      assert_in_delta lower, subject.first[:data_lower_limit], 0.01
     end
   end
 
   def self.it_has_status_counts_of(in_control:, out_of_control_upper:, out_of_control_lower:)
     it "has the correct number of in-control points" do
-      assert_equal in_control, subject.where(control_status: "in_control").count
+      assert_equal in_control, subject.where(rule_in_control: true).count
     end
 
     it "has the correct number of out-of-control-upper points" do
-      assert_equal out_of_control_upper, subject.where(control_status: "out_of_control_upper").count
+      assert_equal out_of_control_upper, subject.where(rule_out_of_control_upper: true).count
     end
 
     it "has the correct number of out-of-control-lower points" do
-      assert_equal out_of_control_lower, subject.where(control_status: "out_of_control_lower").count
+      assert_equal out_of_control_lower, subject.where(rule_out_of_control_lower: true).count
     end
   end
 
   def self.it_is_out_of_control_at(upper_samples:, lower_samples:)
-    upper_samples.each do |sample_id|
-      it "it is out-of-control-upper at sample #{sample_id}" do
-        control_status = subject.where(sample_id: sample_id).select(:control_status).first
-        refute_nil control_status, "no matching out-of-control-upper sample was found for #{sample_id}"
-        assert_equal "out_of_control_upper", control_status[:control_status]
+    upper_samples.each do |id_sample|
+      it "it is out-of-control-upper at sample #{id_sample}" do
+        control_status = subject.where(id_sample:).select(:rule_out_of_control_upper).first
+        refute_nil control_status, "no matching out-of-control-upper sample was found for #{id_sample}"
+        assert_equal true, control_status[:rule_out_of_control_upper]
       end
     end
 
-    lower_samples.each do |sample_id|
-      it "it is out-of-control-lower at sample #{sample_id}" do
-        control_status = subject.where(sample_id: sample_id).select(:control_status).first
-        refute_nil control_status, "no matching out-of-control-lower sample was found for #{sample_id}"
-        assert_equal "out_of_control_lower", control_status[:control_status]
+    lower_samples.each do |id_sample|
+      it "it is out-of-control-lower at sample #{id_sample}" do
+        control_status = subject.where(id_sample:).select(:rule_out_of_control_lower).first
+        refute_nil control_status, "no matching out-of-control-lower sample was found for #{id_sample}"
+        assert_equal true, control_status[:rule_out_of_control_lower]
       end
     end
   end