Calculation field
The values in Calculation fields are calculated from the expressions specified by you in Memento Script, defined herein.
The following types of expressions are supported:
- Numeric
- Expressions involving numbers
- String
- Strings can also be added together, compared, etc
- Boolean
- Expressions that evaluate to true (1.0) and false (0.0)
Numeric and string types can not be mixed in a left / right operand pair.
Result type
For each calculation, there must be a correct result type set:
- Real result and Integer result
- are used for expressions with a numerical result
- Date/Time result
- is used to represent the result in the form of date and time. The calculation result is interpreted as the number of seconds that has passed since January 1, 1970 (UNIX time).
- Date result
- is the same as the previous type, but displays only the date
- String result
- is used for expressions that contain string manipulations or functions that return a string
Field value references and other variables
The values of other fields in the same entry and fields in linked libraries may be referenced by enclosing them within a hash mark and open brace #{ and a closed brace }. Other values can be referenced in similar fashion, such as the number of fields in an entry. These constitute read-only variables. For example, consider the following expression:
#{field name 1} + #{library 2.field name 2}
String values must be enclosed by single-quote (apostrophe) characters:
'Result: ' + '#{string field 1}' + '#{string field 2}'
Field references may be typed into the Expression area, or they may be inserted by pressing the +Field button and selecting from among the fields listed.
Values of variables cannot be changed by the Calculation field.
Operators
The following operators are supported:
Symbol | Operator | Description |
---|---|---|
( ) |
open parenthesis closed parenthesis |
Grouping Group together a subexpression within an outer expression Example: (subexpression 1) + (subexpression 2) |
- + |
minus plus |
Unary number Example: -5 or +10 |
+ - |
addition subtraction |
Binary Example: #{a} + #{b} - 1 |
* / |
multiplication division |
Binary Example: 6 / (8 * 13) |
% | modulo | Binary, integer remainder after division Example: #{months} % 12 |
== != < <= > >= |
equal not equal less less or equal greater greater or equal |
Binary, relational Example: if( #{count} <= #{max} , #{count} , #{max} ) |
&& !! |
and or |
Binary, for TRUE and FALSE (Boolean) Example: if( #{Done} !! ( #{Able} && #{Trying} ) , 'Raise' , 'No raise' ) |
! | not | Unary, for TRUE or FALSE (Boolean) Example: if( ! #{Done} , 'Work' , 'Relax' ) |
Functions
Functions are available to assist in crafting expressions to calculate a final result. Function calls may be typed into the expression, or the user may use the +Function button to display a tabbed list of functions that may be used.
- Note
- The rest of this section documents the available functions. However, while the functions may be better explained here, it may be incomplete or even incorrect. The menus of available functions within Memento when using the +Function button are quite useful and will always be more recently updated than what is documented here.
Math functions
Date/Time Functions
Function | Arguments | Returns |
---|---|---|
datediff | date, date |
number of days between the 2 dates |
dateadd 4 arguments |
date, interval days, interval months, interval years |
date incremented by the date interval |
dateadd 7 arguments |
date, interval seconds, interval minutes, interval hours, interval days, interval months, interval years |
date incremented by the time interval |
formatDate | seconds since start of Jan 1 1970 | equivalent date string |
formatDateTime | seconds since start of Jan 1 1970 | equivalent date/time string |
formatTime | seconds since start of Jan 1 1970 | equivalent time string |
now | The current time in seconds since the start of Jan 1 1970 Uses Universal Time (UTC) regardless of local settings or time zone | |
relativeTimeStr | start time | String describing the elapsed time since the given start time |
formatDuration | seconds | duration as a string formatted as MM:SS or H:MM:SS |
String functions
Logical functions
Function | Arguments | Returns |
---|---|---|
if | expression, value if TRUE, value if FALSE |
3 arguments One value if a logical expression is TRUE (not equal to 0.0) and another if it is FALSE (equal to 0.0) Read it as "If expression is true, then value 1, else value 2" Example: if(#{remaining} == 0, 'Done', 'Incomplete') |
switch | expression, value/result pairs, default result |
1+(2*#pairs)+1 arguments The final result based on matching the expression against the paired values to identify the paired result (or else the default result) to be used Example: switch(#{count}, 1, 'One', 2, 'Two', 'Many') |
Link to Entry
Use the following syntax to get access to the values of Link to Entry and other linking fields:
#{link field name.child field name}
where link field name is the name of a Link to Entry or similar field, child field name is the name of a field of a related entry.
If a link field contains several links, then use an index (starting from zero) to get access to them:
#{link field name@0.child field name}, #{link field name@1.child field name}, …
You can specify one of the supported aggregation functions instead of the index:
#{link field name@sum.child field name}
This expression returns the sum of values of field child field name for all entries included into link field name. The functions supported are: sum, avg, min, and max.
Use the following syntax to get the number of entries in the library referenced by link field name:
#{link field name@size}
Examples
Example: Single-operator expression
Entries contain fields: Price, Count
We add a Calculation field Sum by using the following expression:
#{Price} * #{Count}
Example: Percentage
Entries contain fields: Count, Total
We add a Calculation field Percentage by using the following expression:
(#{Count } / #{ Total }) * 100
Example: Duration
Entries contain fields: StartDateTime, EndDateTime
We add a Calculation field Duration by using the following expression (result is the number of seconds):
#{EndDateTime} - #{StartDateTime}
Example: Days
Entries contain fields: StartDate, EndDate
We add a Calculation field Days by using the following expression:
datediff(#{EndDate}, #{StartDate})
Example: Days left
Entries contain field: Time
We add a Calculation field Days Left by using the following expression:
if( #{Time} > now() , rint((#{Time} - now())/(60*60*24)) , 'in the past' )
Example: References
There’s a library Order containing orders and a library Item containing items. Library Order contains a link to library Item and a numeric field Count. Library Item contains field Price.
To calculate the cost of the order, add Calculation field Sum using the following formula:
#{count} * #{item.price}
If an order can make a reference to several different items, their total cost can be calculated:
#{item@sum.price}
The most expensive item:
#{item@max.price}
The cheapest item:
#{item@min.price}
The average price for the item:
#{item@avg.price}
- Name
- Textual, case-insensitive field identifier that can include spaces; it's best to avoid characters that can be used as operators, though (standard across all field types)
- Hint
- Textual, case-insensitive field identifier that can include spaces
Advanced Parameters
- Thousands separators
- If the chosen result type is Integer or Real, use spaces as separators to break the value into thousands. By default, it will not.
Display Options
- Display in the list as
- Select among the following roles for the current field in the entries list:
- As a Regular field
- As an Entry Name
- As an Entry Description
- As an Entry Status
- Use in Calendar as
- None / Duration, mins / Duration, hours
- The field name
- Display the name of the field in the card entry (By default, On). By this, it is meant that the field name will or will not be displayed on either the Entry View card or the Entry Edit card.
- Font
- Choices are:
- Family: Regular, Light, Condensed, Thin, Medium. By default, Regular.
- Style: Normal, Bold, Italic, Bold Italic. By default, Normal.
- Size: By default, 18. Direct entry to change.
- Color: By default, White. Palette of 20 colors, backed up by a continuously variable color chooser.
- Dependencies
- Ability to add one or more visibility dependencies upon fields with qualifying types.