Which Variables go on which side of a Karnaugh Map - boolean

For a Karnaugh map of three or more variables deciding which side the variables go makes the solution easier to spot and simpler. But how do you know which side which variables go on.
eg. For variables x, y and z; You could have x and y as column headers and z as a row header or you could have y and z as column headers and x as a row header which would give two different tables

For maps with up to four variables, it is a matter of taste, which variable is put at which side. However, Mahoney maps as extension of Karnaugh maps for five and more variables do require a certain ordering along the side.
Expression for the following examples:
abcd!e + abc!de
Five-input Mahoney map:
Equivalent Karnaugh map:
de de
00 01 11 10 00 01 11 10
abc +---+---+---+---+ abc +---+---+---+---+
000 | 0 | 0 | 0 | 0 | 001 | 0 | 0 | 0 | 0 |
+---+---+---+---+ +---+---+---+---+
010 | 0 | 0 | 0 | 0 | 011 | 0 | 0 | 0 | 0 |
+---+---+---+---+ +---+---+---+---+
110 | 0 | 0 | 0 | 0 | 111 | 0 | 1 | 0 | 1 |
+---+---+---+---+ +---+---+---+---+
100 | 0 | 0 | 0 | 0 | 101 | 0 | 0 | 0 | 0 |
+---+---+---+---+ +---+---+---+---+
It is always possible to swap variables as shown here:
de de
00 01 11 10 00 01 11 10
abc +---+---+---+---+ abc +---+---+---+---+
000 | 0 | 0 | 0 | 0 | 001 | 0 | 0 | 0 | 0 |
+---+---+---+---+ +---+---+---+---+
010 | 0 | 0 | 0 | 0 | 011 | 0 | 0 | 0 | 0 |
+---+---+---+---+ +---+---+---+---+
110 | 0 | 0 | 0 | 0 | 111 | 0 | 1 | 0 | 1 |
+---+---+---+---+ +---+---+---+---+
100 | 0 | 0 | 0 | 0 | 101 | 0 | 0 | 0 | 0 |
+---+---+---+---+ +---+---+---+---+
Here you can find a nice online-tool to draw and simplify Karnaugh-Veitch/Mahoney maps.

Related

double precision in MATLAB

So double precision takes 64 bits in MATLAB. I know that 0 or 1 will take one bit.
But when I type realmax('double') I get a really big number 1.7977e+308. How can this number be saved in only 64 bits?
Would appreciate any clarafication. Thanks.
This is not a MATLAB question. A 64-bit IEEE 754 double-precision binary floating-point format is represented in this format:
bit layout:
| 0 | 1 | 2 | ... | 11 | 12 | 13 | 14 | ... | 63 |
| sign | exponent(E) (11 bit) | fraction (52 bit) |
The first bit is the sign:
0 => +
1 => -
The next 11 bits are used for the representation of the exponent. So we can have integers all the way to +2^10-1 = 1023. Wait... that does not sound good! To represent large numbers, the so-called biased form is used in which the value is represented as:
2^(E-1023)
where E is what the exponent represents. Say, The exponent bits are like these examples:
Bit representation of the exponent:
Bit no: | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 |
Example 1: | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
Example 2: | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
Example 3: | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 |
Example 4: | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0 |
Example 5: | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
Base 10 representation:
Example 1 => E1: 1
Example 2 => E2: 32
Example 3 => E3: 515
Example 4 => E4: 2046
Example 5 => E4: Infinity or NaN (**** Special case ****)
Biased form:
Example 1 => 2^(E1-1023) = 2^-1022 <= The smallest possible exponent
Example 2 => 2^(E2-1023) = 2^-991
Example 3 => 2^(E3-1023) = 2^-508
Example 4 => 2^(E4-1023) = 2^+1023 <= The largest possible exponent
Example 5 => 2^(E5-1023) = Infinity or NaN
When E meets 0 < E < 2047 then the number is known as a normalized number represented by:
Number = (-1)^sign * 2^(E-1023) * (1.F)
but if E is 0, then the number if known as a denormalized number represented by:
Number = (-1)^sign * 2^(E-1022) * (0.F)
Now F is basically the what is determined by the fraction bits:
// Sum over i = 12, 13, ..... , 63
F = sum(Bit(i) * 2^(-i))
and Bit(i) refers the ith bit of the number. Examples:
Bit representation of the fraction:
Bit no: | 12 | 13 | 14 | 15 | ... ... ... ... | 62 | 63 |
Example 1: | 0 | 0 | 0 | 0 | 0 ... .... 0 | 0 | 1 |
Example 2: | 1 | 0 | 0 | 0 | 0 ... .... 0 | 0 | 0 |
Example 3: | 1 | 1 | 1 | 1 | 1 ... .... 1 | 1 | 1 |
F value assuming 0 < E < 2047:
Example 1 => 1.F1 = 1 + 2^-52
Example 2 => 1.F2 = 1 + 2^-1
Example 3 => 1.F3 = 1 + 1 - 2^-52
But when I type realmax('double') I get a really big number
1.7977e+308. How can this number be saved in only 64 bits?
realmax('double')'s binary representation is
| sign | exponent(E) (11 bit) | fraction (52 bit) |
0 11111111110 1111111111111111111111111111111111111111111111111111
Which is
+2^1023 x (1 + (1-2^-52)) = 1.79769313486232e+308
I took some definitions and examples from this Wikipedia page.

Is AB the equivalent of A^B?

Doing some boolean algebra. I am under the assumption that AB(B+~C) can also be written as
A^B ^ (B+~C) OR (A AND B)AND(B OR ~C)
Is this true?
If that is the case then for the following expression I simplified that if
A=1 B=1 C=0
A^B(B^~C)
= (1^1) ^ (1 OR 1)
= 1 ^ 1
= 1
= True`
Does this make sense or does
AB
mean something else entirely?
Yes, this is correct. AB and A∧B are equivalent. And
A | B | C | A∧B | B∨¬C | (A∧B)∧(B∨¬C)
-------------------------------------
0 | 0 | 0 | 0 | 1 | 0
0 | 0 | 1 | 0 | 0 | 0
0 | 1 | 0 | 0 | 1 | 0
0 | 1 | 1 | 0 | 1 | 0
1 | 0 | 0 | 0 | 1 | 0
1 | 0 | 1 | 0 | 0 | 0
1 | 1 | 0 | 1 | 1 | 1
1 | 1 | 1 | 1 | 1 | 1

SQL query help: Calculate max of previous rows in the same query

I want to find for each row(where B = C = D = 1), the max of A among its previous rows(where B = C = D = 1) excluding its row after its ordered in chronological order.
Data in table looks like this:
+-------+-----+-----+-----+------+------+
|Grp id | B | C | D | A | time |
+-------+---- +-----+-----+------+------+
| 111 | 1 | 0 | 0 | 52 | t |
| 111 | 1 | 1 | 1 | 33 | t+1 |
| 111 | 0 | 1 | 0 | 34 | t+2 |
| 111 | 1 | 1 | 1 | 22 | t+3 |
| 111 | 0 | 0 | 0 | 12 | t+4 |
| 222 | 1 | 1 | 1 | 16 | t |
| 222 | 1 | 0 | 0 | 18 | t2+1 |
| 222 | 1 | 1 | 0 | 13 | t2+2 |
| 222 | 1 | 1 | 1 | 12 | t2+3 |
| 222 | 1 | 1 | 1 | 09 | t2+4 |
| 222 | 1 | 1 | 1 | 22 | t2+5 |
| 222 | 1 | 1 | 1 | 19 | t2+6 |
+-------+-----+-----+-----+------+------+
Above table is resultant of below query. Its obtained after left joins as below. Joins are necessary according to my project requirement.
SELECT Grp id, B, C, D, A, time, xxx
FROM "DCR" dcr
LEFT JOIN "DCM" dcm ON "Id" = dcm."DCRID"
LEFT JOIN "DC" dc ON dc."Id" = dcm."DCID"
ORDER BY dcr."time"
Result column needs to be evaluated based on formula I mentioned above. It needs to be calculated in same pass as we need to consider only its previous rows. Above xxx needs to be replaced by a subquery/statement to obtain the result.
And the result table should look like this:
+-------+-----+-----+-----+------+------+------+
|Grp id | B | C | D | A | time |Result|
+-------+---- +-----+-----+------+------+------+
| 111 | 1 | 0 | 0 | 52 | t | - |
| 111 | 1 | 1 | 1 | 33 | t+1 | - |
| 111 | 1 | 1 | 1 | 34 | t+2 | 33 |
| 111 | 1 | 1 | 1 | 22 | t+3 | 34 |
| 111 | 0 | 0 | 0 | 12 | t+4 | - |
| 222 | 1 | 1 | 1 | 16 | t | - |
| 222 | 1 | 0 | 0 | 18 | t2+1 | - |
| 222 | 1 | 1 | 0 | 13 | t2+2 | - |
| 222 | 1 | 1 | 1 | 12 | t2+3 | 16 |
| 222 | 1 | 1 | 1 | 09 | t2+4 | 16 |
| 222 | 1 | 1 | 1 | 22 | t2+5 | 16 |
| 222 | 1 | 1 | 1 | 19 | t2+6 | 22 |
+-------+-----+-----+-----+------+------+------+
The column could be computed with a window function:
CASE WHEN b = 1 AND c = 1 AND d = 1
THEN max(a) FILTER (WHERE b = 1 AND c = 1 AND d = 1)
OVER (PARTITION BY "grp id"
ORDER BY time
ROWS BETWEEN UNBOUNDED PRECEDING AND 1 PRECEDING)
ELSE NULL
END
I didn't test it.

pyspark piplineRDD fit to Dataframe column

Before everything i'm new guy in python and spark world.
I have homework from university but i stuck in one place.
I make clusterization from my data and now i have my clusters in PipelinedRDD
aftre this:
cluster = featurizedScaledRDD.map(lambda r: kmeansModelMllib.predict(r))
cluster = [2,1,2,0,0,0,1,2]
now now i have cluster and my dataframe dataDf i need fit my cluster like a new column to dataDf
i Have: i Need:
+---+---+---+ +---+---+---+-------+
| x | y | z | | x | y | z |cluster|
+---+---+---+ +---+---+---+-------+
| 0 | 1 | 1 | | 0 | 1 | 1 | 2 |
| 0 | 0 | 1 | | 0 | 0 | 1 | 1 |
| 0 | 8 | 0 | | 0 | 8 | 0 | 2 |
| 0 | 8 | 0 | | 0 | 8 | 0 | 0 |
| 0 | 1 | 0 | | 0 | 1 | 0 | 0 |
+---+---+---+ +---+---+---+-------+
You can add index using zipWithIndex, join, and convert back to df.
swp = lambda x: (x[1], x[0])
cluster.zipWithIndex().map(swp).join(dataDf.rdd.zipWithIndex().map(swp)) \
.values().toDF(["cluster", "point"])
In some cases it should be possible to use zip:
cluster.zip(dataDf.rdd).toDF(["cluster", "point"])
You can follow with .select("cluster", "point.*") to flatten the output.

how to simplify this Boolean expression to 3 literals?

How do I simplify this to 3 literals/letters?
= LM'+LN+N'B
How would you simplify this boolean expression? I don't know which boolean laws I need to use. I tried but I couldn't get it down to 3 literals only 4.
I have also not been able to reduce your expression to three literals.
The Karnaugh map:
BL
00 01 11 10
+---+---+---+---+
00 | 0 | 1 | 1 | 1 |
+---+---+---+---+
01 | 0 | 1 | 1 | 0 |
MN +---+---+---+---+
11 | 0 | 1 | 1 | 0 |
+---+---+---+---+
10 | 0 | 0 | 1 | 1 |
+---+---+---+---+
From looking at the map, you can see that three terms are needed to cover the nine minterms (depicted by "1") in the map. Each of the terms has two literals and covers four minterms. A term with just one literal would cover eight minterms.