Obsidian Sigma
Obsidian is a great markdown-based note taking app. One of the key aspects of Obsidian is it's extensibility by using additional plugins.
Sigma is a plugin to enable using blocks within a note as calculation sheets.
Features
- Calculation expressions with proper operator precedence
- Automatic block level totals
- Support for multiple blocks in a single note
- Hierarchy and subtotals
- Variable assignment and evaluation
- Built in scientific functions
- Control over output number formatting
- Output in clean HTML tables for easy sharing
- Syntax coloring for expressions in output including dark theme
- Supported on desktop and mobile
Usages
- Financial planning,
- Expense tracking,
- Conversions,
- Miscllaneous calculations,
- And much more
Installation
- Install the Sigma plugin from the Obsidian community plugins list
Guide
- Use a code block (3 backquote characters) with a type sigma
- Write expressions on each line
- Each expression is evaluated
- All expressions in a block are totaled
- Once you exit the block (editing cursor moves out, or switch to read mode), the block is rendered as an HTML table with expression values and block totals
Exampels
Simple Calculation List
```sigma
12+3+5
13+9+44
2+3*4
2*3+4
2*(3+4)
```
Produces
1 |
12+3+5 |
20 |
2 |
13+9+44 |
66 |
3 |
2+3*4 |
14 |
4 |
2*3+4 |
10 |
5 |
2*(3+4) |
14 |
124 |
Word and Value
You can use a word as a prefix for an expression, separated by a colon character :
```sigma
test1: 12/3
test2: 98.7
```
Produces
1 |
test1: 12/3 |
4 |
2 |
test2: 98.7 |
98.7 |
102.7 |
Words and Expressions
You can also use multiple words in a sentence as a prefix, however, you cannot embed numbers or other special characters within the sentence.
```sigma
multipe word sentence: 7+9
word1
word2: 2*9
```
Produces
1 |
multipe word sentence: 7+9 |
16 |
2 |
word1 |
0 |
3 |
word2: 2*9 |
18 |
34 |
Negative Values
```sigma
-234
```
Produces
1 |
-234 |
-234 |
Hierarchy
Create hierarchies by using space indentation in code blocks. Sigma automatically adds all sub-items to the parent line
```sigma
Cat1
Item1: 5
Item2: 6
Cat2
Item3: 7
Item4: 8
```
Produces
1 |
Cat1 |
11 |
2 |
....Item1: 5 |
5 |
3 |
....Item2: 6 |
6 |
4 |
Cat2 |
15 |
5 |
....Item3: 7 |
7 |
6 |
....Item4: 8 |
8 |
26 |
Assignment and variable
Variables can be evaluated later within the block
```sigma
someVar = 200;
someVar * 10;
```
Produces
1 |
someVar=200; |
200 |
2 |
someVar*10; |
2,000 |
2,200 |
Built-in Functions
A number of scientific functions are built-in
```sigma
PI=3.141592276
sin(PI/4)
cos(PI/2)
tan(PI/4)
asin(1)
acos(0)
atan(0.7)
abs(2-4)/(2-4)
clamp(29,0,1)
```
Produces
1 |
PI=3.141592276 |
3.142 |
2 |
sin (PI/4) |
0.707 |
3 |
cos (PI/2) |
0 |
4 |
tan (PI/4) |
1 |
5 |
asin (1) |
1.571 |
6 |
acos (0) |
1.571 |
7 |
atan (0.7) |
0.611 |
8 |
abs (2-4)/(2-4) |
-1 |
9 |
clamp (29,0,1) |
1 |
8.601 |
Line References
Even without explicitly naming a variable, each line is automatically referenceable by using Line and the line number
```sigma
Header1
Value1: 1
Value2: 2
Line1+6
```
Produces
1 |
Header1 |
3 |
2 |
.....Value1: 1 |
1 |
3 |
.....Value2: 2 |
2 |
4 |
Line1+6 |
9 |
12 |
Complex Expressions
You can use parenthesis for compound expressions as you would expect in a programming language.
```sigma
abs(12-3)/(12-3)+9
```
Produces
1 |
abs (12-3)/(12-3)+9 |
10 |