This model was created by using an equation like this, where t went from 0 to 360.0
x = cos(t) * (sin(t*10)*1+5)
y = sin(t) * (sin(t*10)*1+5)In essence, wrapping a 10x compressed sine wave around a circle with a radius of 5 (+1/-1). This was then projected into a sketch, extruded, and additional features were added.
Today I learned that Creo Parametric has first class support for equations which can be turned into sketch items, and the incorporated into a model. In this example I created a sine wave.
y = sin(x*2) * 100And told Creo to extend it from x=0 to x=900. Here is a picture of editing the equation.
Once I had that curve defined, I created a sketch on the same plane, and then used the “Project” tool to project the sinewave into the current sketch. After adding sides and a bottom, I had a closed shape.
From there it was a simple matter to extrude, offset, cut, and add some colors.
We’ve elected to use PTC Creo 7 for engineering design software. A lot to learn, but here is a start:
I’ve been interested in automating the process of designing building structures according to a set of input parameters, and having a software application determine all of the pieces necessary to meet structural engineering principals and applicable building codes.
An ideal tool for this is OpenSCAD, which is a 3D modeling program that uses code as input.
There is a nice Python library which is a wrapper around the OpenSCAD input language: https://github.com/SolidCode/SolidPython
Here is a proof of concept. It’s working well so far!
Some years ago I was working on interlocking board game tiles so that you could have a small box that would turn into a large game. Some point between then and not it occurred to me that each side of each hex needed to have 2 connection points, not one.
Browser security policies prevent frames from interacting with each other if they are not from the same origin (like domain but even more specific).
However, frames can pass messages to each other. Here is how you can implement cross-origin iframe auto-resizing based on window.postMessage.
Lets assume we have a parent page that looks like this:
<html>
<head>
<title>Parent Page</title>
</head>
<body>
...
[iframe id="frame1" src="https://otherdomain.com/frame1.html"]
</body>
</html>
(assume [] is <> above, sorry about over protective content escaping in wordpress.com)
To enable auto-resizing on this page, add some script to the end of the <head></head> section (or just before </body> if that is where you put them).
This listens for a “message” event and will check to see if it has an action of “resize”. If so it will update the specified id’s height.
<script>
window.addEventListener("message",function(e){
if(e.data.action=='resize') {
document.getElementById(e.data.id).style.height = e.data.height+'px';
}
},
false
);
</script>
On the embedded frame source, you need an onload event to send a message:
window.onload = function() {
window.parent.postMessage({action:'resize',id:'frame1',height:document.body.scrollHeight+20},'*');
};
Note that we need to pass “frame1” which is the ID of the frame on the parent page.
Then the frames should auto-size to their content.
One day, suddenly, we couldn’t reload a production backup. Oh no! It took a bit of digging around but here is the issue, should you find yourself running into it:
Using the InnoDB COMPACT ROW_FORMAT, there are some rules InnoDB uses to decide how much data to put on the first page and how much to put on overflow pages. While VARCHAR and TEXT type columns are typically stored on overflow pages with no problem, when using the COMPACT row format, up to the first 767 bytes of each field will be stored on the primary page.
This error happens when the amount of actual data exceeds the allows limit for a row size on the main page, which is about 50% of the innodb_page_size variable.
https://mariadb.com/kb/en/library/innodb-compact-row-format/
If you have a circumstance with say, 11 TEXT or VARCHAR fields, each with at least 767 bytes of data, and running an innodb_page_size of 16k (which results in 8126 being max row size on main page) …… then 767*11=8437 stored on main page is greater than 8126 which is the “maximum allowed size for a record on index leaf page”, and you will get this error.
The solution is to investigate the use of either DYNAMIC or COMPRESSED row format, depending on your application.
If you need a super easy way to reset your MySQL or MariaDB root password because you locked yourself out, this is how it can be done.
[server] skip-grant-tables
# mysql
MariaDB> use mysql;
MariaDB> update user set
Password=PASSWORD("yourpass"),
authentication_string=PASSWORD("yourpass")
where User='root';
You are back in action! Don’t forget to re-enable remote access.
Recipe for really outstanding hot cocoa:
Put it on the stove and stir until hot and dissolved. It is very rich and exceptionally chocolaty.
Microsoft has been doing a lot to promote linux interoperability on windows. I see this as a great step in the right direction, after decades of a closed and exclusive culture that has been a pain for cross-os users like myself.
Here is a quick and dirty rundown of how (March 2019) to install Ubuntu on Windows 10:
See here for the full rundown: https://docs.microsoft.com/en-us/windows/wsl/install-win10
Before installing any Linux distros for WSL, you must ensure that the “Windows Subsystem for Linux” optional feature is enabled:
Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Windows-Subsystem-Linux
Go to the Microsoft Store and search for Ubuntu. Install it.
—
Once you are in Ubuntu, there are a few things to do that will make everything nicer…
Fix character encoding issue (until this is fixed upstream)
sudo gunzip –keep /usr/share/i18n/charmaps/UTF-8.gz
sudo dpkg-reconfigure –frontend=noninteractive locales
The Gahooa Perspective 