Welcome

Create documents with working, well-documented calculations!

This is a live text editor. You can click anywhere and start typing. The calculation cells are also live. You can click on one and edit it. They will all update if you close a calculation cell with Enter.

Calculations

To create a calculation cell, select a spot and type Alt+C or hit the button. Write your calculation into the cell and write a “?” sign where the result should appear. Hit the Enter key and a completed calculation will appear, like these:

You can assign a result to a variable:

… and then use the variable in a calculation:

Rounding Results

You can define how numeric results are rounded. The next line specifies that subsequent decimal fractions will be rounded so that no more than 3 significant digits appear.

Unit-Aware Calculations

Physical units can be part of your calculations. Hurmet will automatically convert the units.
Write unit names between single quotes, as in 'meter', and write a ?? where you want the result of a unit-aware calc.

Hurmet also does a unit-compatibility check.

Vectors

Calculations can be done on vectors. Say that we want to build a cylindrical water tank in 5-foot courses.

We’ll calculate values for each course, all at once, using vectors. Each vector element represents one course.

The next line creates a vector. The syntax is [start:step:end...].

, water depth at the bottom of each course

, lateral hydrostatic pressure

, hoop tension in each course

Vectors can replace many spreadsheet calculations. Then all of the expressions and values are open to view. That extra information helps you to avoid the errors that creep into spreadsheets.

Data Frames

Data can be stored in a tabular format:            

Later, you can access the data:

Remote Data

Such data can be stored in a remote file. Say that we want to engineer a steel end-plate connection. The calculation could begin by fetching a chunk of data about steel shapes and loading that data into a variable, like this:

From that, we can load data into variables for individual dimensions.

Beam properties:

Column properties:

Now we can use those variables to do calculations. For an actual steel connection of this sort, a calculation would typically run to about three pages. We’ll do just a few lines.

Check panel zone

, panel zone shear demand

, axial load demand in column from structural analysis

Rational Numbers

Hurmet numbers are rational numbers of arbitrary precision. Unlike most programming languages, Hurmet will do the following comparison correctly:

Hurmet can handle bigger numbers than many languages:

Matrix Inversion

Hurmet can solve a system of linear equations via matrix inversion.

The system:      when restated in matrix format is:   

We can invert the first matrix and multiply it times both sides. That solves for each variable.

Reviews

Reviewers can write comments that are visibly different than the document.

You can save a document snapshot and later display the difference between the snapshot and the current document.

Annotations

User-Defined Functions

You can write your own Hurmet functions. The one below implements an infinite series developed by Francois Viète in 1597, to estimate the value of π. He derived this series:

Here’s the function:

… and now we’ll call the function and tell it to calculate the first ten terms of the series:

, good to 6 significant digits. Not bad for ten terms.

Drawings

Hurmet’s draw environment enables function plotting. For instance, to get a sine wave, one can write the following code into a math zone:

draw()
    title "sin x"
    frame 250, 150
    view -5, 5, -3
    axes 2, 1, "labels"
    strokewidth 2
    plot sin(x), 51
    text [1.6, 1.35], "sin x"
end