Hardware: supplies
Self-tutoring about home maintenance: the tutor mentions visiting the hardware store. When one needs to do repairs, sometimes the way to start is just to see what’s available. It takes time, and an open mind. It seems best to do …
Author: Jack
Comp sci: regular expressions: caret, part 1
Self-tutoring about regular expressions: the tutor mentions a use of the caret symbol, ^. It seems that, in regular expressions, “^” can mean “not” when it’s the first character inside of square brackets. For example, it seems that [^a-zA-Z] would …
Health: dandelion greens, part 2: potential health benefits
Self-tutoring about outdoor lifestyle: the tutor mentions potential health benefits of dandelion greens. I’ve heard over the years that dandelion greens are healthful to eat. Yet, how, in particular? Not too surprisingly, it seems, dandelion greens are a source of …
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Nature: Vancouver Island frog calls in spring: who is it?
Self-tutoring about spring calls from frogs at night-time: the tutor mentions a possible caller from west coast swamps. I mention, back in my post from April 9, about hearing frog and toad calls from the woods in springtime in the …
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Excel: the t function
Self-tutoring about Excel: the tutor mentions another interesting function. In Excel, the t function seems to return the contents of a cell if the cell contains text, but an empty string, aka “”, otherwise. Then, what might qualify as text? …
Retrospect, nature: whose calls were they?
Self-tutoring about nature in Nova Scotia: the tutor reflects on a memory. I recall, as a kid in the Annapolis Valley, the woods behind our house would erupt with high-pitched calls in the spring. To me, it kind of sounded …
PHP: intval, part 1: surprising output
Self-tutoring about PHP’s intval function: the tutor mentions a surprise. I was reading about PHP’s intval function today. It’s meant, as I understand, to convert a decimal number to an integer, by just keeping the integer part. Putting it in …
Excel: depreciation: db function
Self-tutoring about Excel: the tutor mentions another neat function from it, this time about depreciation. Let’s imagine one wants to calculate declining-balance depreciation for the following case: Purchase price of 10000, salvage of 1000, useful life of ten years: what …
Excel: function to calculate days between two dates
Self-tutoring about Excel: the tutor mentions its days function. As I understand, =days(later_date, earlier_date) will yield the days between those two dates, inclusive of one. For instance, =days(“05-april-2025″,”04-april-2025”) returns 1. For another example, =days(“08-may-2025″,”11-oct-2024”) returns 209. Such is my experience, …
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Excel: pduration function
Self-tutoring about Excel: the tutor mentions pduration. To my understanding, Excel’s pduration(the_rate, amount1, amount2) function calculates the number of periods for an investment of amount1 to be worth amount2 at the_rate per period, compounded. For instance, let’s imagine an investment …